A–Z Medical Terms

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A

Abdomen [Medical_term]
The part of the body between the chest and pelvis.
Abortion [Medical_term]
1. Induced abortion is a procedure done to end pregnancy.
2. Spontaneous abortion is a naturally occurring abortion (also called miscarriage).
3. Therapeutic abortion is an induced abortion required to save the life or health of the mother.
Abrasion [Medical_term]
A wound caused by scraping the skin. A “skinned knee” is a common example.
abscess [Medical_term]
A swollen, inflamed area where pus gathers.
Absorption [Medical_term]
To take in substances through the skin or mucous membranes.
Abstinence [Medical_term]
To hold back or restrain. For example, to refrain from the use of drugs or alcohol, or from having sexual intercourse.
Acclimation [Medical_term]
The process of getting used to a new climate or altitude.
Achilles’ tendon [Medical_term]
The strong tendon at the back of the ankle that attaches the calf muscle to the heel.
Acidosis [Medical_term]
An abnormal condition in the body in which excessive acid lowers the pH of the blood and body tissues.
Acne [Medical_term]
A skin disorder usually found in adolescents and young adults.
Acoustic [Medical_term]
Having to do with sound and hearing.
Acromegaly [Medical_term]
A condition that occurs when the pituitary gland produces too much growth hormone. In adults, this can cause overgrowth of bones that occurs in smaller bones, such as those in the jaw, hands and feet. In children or teenagers, this can cause giantism.
actinic keratosis [Medical_term]
Scaly, pink, gray or tan patches or bumps on the face or scalp, or on the back of the hands. Occur mostly on people who have light skin that has been damaged by the sun.
acupuncture [Medical_term]
An ancient Chinese method to relieve pain or treat disease by inserting needles into various parts of the body.
Acute [Medical_term]
1. Of short course. 2. Severe, but of a short duration. Not chronic.
Addiction [Medical_term]
Strong dependence or habitual use of a substance or practice, despite the negative consequences of its use.
Addison’s disease [Medical_term]
An ailment characterized by underfunctioning of the adrenal glands. Characterized by anemia, weakness, low blood pressure and brownish discoloration of the skin.
adenitis [Medical_term]
Swelling of a gland.
adenoids [Medical_term]
Glandular tissue in the back of the throat that may swell, especially during childhood, obstruct breathing and speaking, and lead to ear infections.
adenoma [Medical_term]
A noncancerous tumor of glandular tissue.
adenovirus [Medical_term]
One of the viruses that cause the common cold.
ADH [Medical_term]
Antidiuretic hormone. One of the hormones produced by the pituitary gland. A shortage of this hormone causes increased loss of body fluids through the kidneys.
adhesion [Medical_term]
The sticking of one surface to another. This can occur when scar tissue causes organs or loops of intestine to stick together. Occasionally, these adhesions may produce an intestinal obstruction or other malfunction by twisting or distorting the organ.
adipose fatty cells [Medical_term]
Special cells in which fat is stored when a person’s caloric intake is greater than that required by one’s metabolism.
adrenal glands [Medical_term]
Located on top of the kidneys, these glands produce hormones helpful in regulating the body’s metabolism.
adrenaline [Medical_term]
Epinephrine. One of several hormones produced by the adrenal glands.
aerobic [Medical_term]
Requiring the use of oxygen. Exercise that conditions the heart and lungs by increasing the efficiency of oxygen intake by the body.
afterbirth [Medical_term]
The placenta, which is attached to the fetus by the umbilical cord and must be delivered after the baby.
AIDS [Medical_term]
Acquired immunodeficiency syndrome. A disease of the immune system caused by the HIV virus.
airway [Medical_term]
The passage by which air enters and exits the lungs.
albinism [Medical_term]
The absence of all normal body pigmentation at birth, a condition that can occur in all races.
albino [Medical_term]
A person with albinism.
albumin [Medical_term]
A water-soluble protein found in milk, egg, muscle, blood and many vegetable tissues and fluids.
aldosteronism [Medical_term]
A condition resulting when the adrenal glands produce too much of the hormone aldosterone, which regulates fluids and salt in the body.
alimentary [Medical_term]
Having to do with food or nutrition. The alimentary tract is the digestive tract.
allergen [Medical_term]
A substance capable of producing an allergic reaction.
allergy [Medical_term]
An exaggerated immune response to substances in the environment.
alopecia [Medical_term]
Hair loss, especially of the head.
alpha1-antitrypsin deficiency [Medical_term]
Congenital lack of an enzyme that leads to cirrhosis of the liver and obstructive lung disease.
altitude sickness [Medical_term]
A potentially fatal illness caused by being at altitudes high enough to reduce the amount of oxygen available to the body.
alveoli [Medical_term]
The sacs in the lungs at the ends of the smallest airways where oxygen is exchanged for carbon dioxide in the blood.
amblyopia [Medical_term]
Impaired vision without an apparent cause.
ambulatory [Medical_term]
Able to walk. Not confined to bed.
amenorrhea [Medical_term]
Absence of menstrual periods.
amnesia [Medical_term]
Partial or total loss of memory, usually as the result of psychological trauma or stress, or physical damage to the brain from injury, disease, or alcohol or other chronic drug abuse.
amnion [Medical_term]
The membrane enclosing a developing fetus; it’s filled with a protective liquid called amniotic fluid.
amputation [Medical_term]
The surgical removal of a limb or other appendage because of damage by trauma or as a treatment for a variety of potentially life-threatening ailments.
anaerobic exercise [Medical_term]
Brief, intense exercise that leads to an oxygen debt in a certain area of tissue. Weight lifting is an example.
anaphylaxis [Medical_term]
The most severe form of allergy, in which the person’s heart and lungs are unable to keep working, and death occurs unless prompt medical attention is obtained.
androgen [Medical_term]
Any substance that produces male characteristics. Testosterone and androsterone are natural androgens.
anemia [Medical_term]
A decreased ability of the blood to carry oxygen because of a reduction in either the number or quality of the red blood cells.
anesthesia [Medical_term]
Drug-induced loss of feeling or sensation.
anesthetic [Medical_term]
An agent used to produce anesthesia.
aneurysm [Medical_term]
A thin sac caused by a weakened area in the walls of blood vessels or the heart. As an aneurysm increases in size, the sac tends to become thinner, and the risk of its breaking becomes greater.
angina pectoris [Medical_term]
Chest pain caused by decreased oxygen delivery to the heart muscle.
angioma [Medical_term]
A noncancerous tumor made up of many blood vessels.
anhidrosis [Medical_term]
Absence of sweating. An inability to sweat greatly interferes with the body’s ability to control its internal temperature.
ankylosis [Medical_term]
Abnormal stiffening of a joint.
anomaly [Medical_term]
Deviation from normal.
anorchism [Medical_term]
Congenital absence of both testes.
anorexia nervosa [Medical_term]
An eating disorder manifested primarily by a loss of desire or willingness to eat for a variety of psychological reasons.
anosmia [Medical_term]
Loss of the sense of smell.
antepartum [Medical_term]
Occurring before delivery of a baby.
antibody [Medical_term]
A protein produced by the body to neutralize an invading foreign agent or antigen, such as a virus.
antidote [Medical_term]
An agent used to counteract a poison.
antigen [Medical_term]
A foreign agent capable of starting an immune response or causing the body to produce antibodies.
antiserum [Medical_term]
A serum that contains antibodies. Serum from a person or animal with immunity to a certain disease can, in some cases, be used to prevent illness in other people.
anus [Medical_term]
The opening of the rectum.
anxiety [Medical_term]
A feeling of nervousness, uneasiness, apprehension or dread.
aorta [Medical_term]
The large artery that carries blood from the heart to the rest of body.
apathy [Medical_term]
Lack of emotions.
Apgar score [Medical_term]
A scoring method from zero to 10 for describing the health of an infant at birth, based on heart rate, breathing, muscle tone, color and reflex irritability.
aphagia [Medical_term]
Inability to swallow.
aphasia [Medical_term]
A partial or total loss of the power to use or understand words.
aphthous ulcers [Medical_term]
A painful sore in the mouth. Also called a canker sore.
apnea [Medical_term]
Temporary pause in breathing.
appendectomy [Medical_term]
Surgical removal of the appendix.
appendix [Medical_term]
A finger-like appendage near the junction of the large intestine and the small intestine.
areola [Medical_term]
The dark area of the breast surrounding the nipple.
arteriosclerosis [Medical_term]
Commonly called “hardening of the arteries.” An abnormal thickening and loss of elasticity of the wall of the arteries.
arteriovenous malformation [Medical_term]
Abnormal group of dilated blood vessels, most often occurring in the brain.
artery [Medical_term]
A vessel that carries blood away from the heart to various parts of the body.
arthralgia [Medical_term]
Pain in a joint.
arthritis [Medical_term]
Inflammation of a joint.
asbestos [Medical_term]
A fibrous material used to make fireproof materials, electrical insulation, roofing and filters. Asbestos has been linked to a type of lung cancer.
ascites [Medical_term]
Abnormal buildup of fluid in the abdomen that causes distention.
ascorbic acid [Medical_term]
Vitamin C.
asthma [Medical_term]
A chronic disorder characterized by shortness of breath, wheezing, coughing and tightness of the chest.
astigmatism [Medical_term]
An irregularity in the curvature of the lens of the eye, resulting in a blurry or distorted image.
atelectasis [Medical_term]
Collapsed lung. May occur following surgery or after a rib fracture.
atherosclerosis [Medical_term]
A form of arteriosclerosis caused by fatty deposits in the arteries.
athlete’s foot [Medical_term]
A fungal infection of the skin of the feet.
atopy [Medical_term]
A predisposition to allergy that’s inherited from parents. Included disorders are asthma, hay fever and eczema.
atria [Medical_term]
The upper chambers of the heart that receive blood from the veins and pass it to the lower chambers of the heart.
atrophy [Medical_term]
A decrease in the normal size of an organ. Wasting away.
aura [Medical_term]
A peculiar sensation that occurs before other symptoms. An example is the sensation of flashing lights before a migraine headache.
autoimmune disease [Medical_term]
A condition in which antibodies form against one’s own cells.
autotransfusion [Medical_term]
A transfusion using the patient’s own blood.
axilla [Medical_term]
The armpit.

B

bacteremia [Medical_term]
The presence of bacteria in the blood.
bacteria [Medical_term]
Single-celled microorganisms with one of three basic shapes: rod-like (bacilli), spherical (cocci) and spiral (spirilla). Bacteria are commonly thought of as disease-causing agents. But many bacteria are beneficial and don’t cause disease.
bacteriuria [Medical_term]
The presence of bacteria in the urine.
Baker’s cyst [Medical_term]
A swelling of the knee caused by an escape of fluid from a sac behind the knee.
ballism [Medical_term]
Quick, jerking movements that occur in people with chorea.
barium [Medical_term]
A chalky substance used in x-ray studies of the digestive tract to highlight abnormalities.
barotrauma [Medical_term]
Injury caused by pressure differences between the atmosphere and the air-filled spaces in the body. The most common of these injuries are the ear and sinus blocks that can occur during air travel.
Bartholin cyst [Medical_term]
A cyst caused by an infection of the glands on the vaginal wall.
BCG (bacille Calmette-Guerin) vaccine [Medical_term]
A vaccine that offers some protection against tuberculosis. It’s now rarely used in the U.S. because it doesn’t give total protection.
bedsore [Medical_term]
An ulcer caused by chafing or by the pressure of the body against the bed.
Bell’s palsy [Medical_term]
A usually temporary loss of feeling or movement of the face, usually on one side, causing an inability to close the eye or mouth on that side.
bends [Medical_term]
A condition that results from rapidly decreasing atmospheric pressure on the body. Symptoms include joint pain, chest pain, shortness of breath and coma. The condition may be fatal.
benign [Medical_term]
A nonlife-threatening condition. Not malignant. Not cancerous.
benign familial tremor [Medical_term]
An inherited disorder that causes a slow tremor in the hands, head and voice. It may affect only one side of the body, be worse when moving than when resting and worsen with age.
beriberi [Medical_term]
A deficiency disease caused by dietary insufficiency of vitamin B1 (thiamine). Symptoms include general weakness and painful rigidity.
biceps [Medical_term]
A muscle having two heads. The most familiar is the large muscle in the front of the upper arm responsible for flexing the forearm.
bicuspid [Medical_term]
A tooth named for the two-pointed projections on the crown.
bifocals [Medical_term]
Eyeglasses with divided lenses. The two parts of each lens have different strengths, allowing the wearer to focus the eye for either near or distant vision.
bile [Medical_term]
A clear yellow fluid produced by the liver and stored in the gallbladder. Aids in digestion.
bilirubin [Medical_term]
A pigment produced in the liver by the breakdown of hemoglobin from old red blood cells. Bilirubin is normally eliminated in the bile. A variety of diseases may cause bilirubin to collect in the body, resulting in a yellow discoloration of the skin known as jaundice.
binocular [Medical_term]
Using both eyes at the same time. Binocular vision is the most important element of depth perception.
biopsy [Medical_term]
Removal and exam of a tissue sample taken from a living body. This procedure helps determine if the tissue is cancerous.
bipolar affective disorder [Medical_term]
A psychiatric disorder in which the affected person has both depressed and happy, energetic (manic) episodes. This is a newer term for manic-depressive disorder.
blackhead [Medical_term]
A dark-topped plug of fatty material in the opening of a hair follicle. The color is the result of exposure of the fat to the air.
blackout [Medical_term]
1. Short-term loss of vision and consciousness. 2. In an alcoholic person, loss of memory for a period of time.
bladder [Medical_term]
The organ that temporarily stores a substance. Commonly used in reference to the urinary bladder, which holds urine until it’s eliminated.
blepharitis [Medical_term]
Inflammation of the eyelid.
blepharoplasty [Medical_term]
Plastic surgery on the eyelid.
blindness [Medical_term]
Loss of vision. Legally, visual acuity less than 20/200 with glasses.
blister [Medical_term]
Buildup of watery or bloody fluid under the skin.
blood [Medical_term]
The fluid circulating through the heart, arteries and veins. Blood is responsible for transporting oxygen to body tissues, carrying waste products away from the tissues and delivering a wide variety of biochemical substances throughout the body to main.
blood poisoning [Medical_term]
Infection within the circulatory system. A potentially life-threatening condition that requires prompt treatment.
blood pressure [Medical_term]
The pressure exerted by the blood against the walls of the blood vessels.
boil [Medical_term]
A skin infection characterized by a localized buildup of pus.
bone marrow [Medical_term]
The tissue within the cavity of the bones where new blood cells are made.
Borrelia [Medical_term]
A class of disease-causing bacteria that includes the organisms that cause relapsing fever and Lyme disease.
botulism [Medical_term]
An extremely dangerous form of food poisoning caused by the toxin of Clostridium botulinum.
bovine [Medical_term]
Having to do with cattle. For example, bovine insulin is insulin obtained from cattle.
bowel [Medical_term]
The tube involved in digestion and extending from the stomach to the anus. Consists of the small intestine and the large intestine.
Bowen’s disease [Medical_term]
A precancerous skin condition that first appears as psoriasis-like scaling.
bowleg [Medical_term]
A deformity of the legs in which the space between the knees is greater than normal.
brace [Medical_term]
A device used to support a body part, correct or prevent deformities, or control movement.
bradycardia [Medical_term]
Slow heart rate and pulse, usually slower than 60 beats per minute.
Braxton Hicks contractions [Medical_term]
Contractions of the uterus during pregnancy that are sometimes mistaken for labor. Also called false labor.
breasts [Medical_term]
Milk-secreting glands protruding from the upper front part of a woman’s body.
breech birth [Medical_term]
A birth in which the feet or buttocks of the baby appear first through the birth canal.
bridge [Medical_term]
A structure that joins two parts. For example, a dental bridge contains artificial teeth and joins the natural teeth at either end.
Bright’s disease [Medical_term]
Nephritis. A group of kidney diseases manifested by albumin in the urine and edema (swelling).
bronchi [Medical_term]
The tubular passages, also called bronchial tubes, that carry air into the lungs.
bronchiolitis [Medical_term]
An infection of the bronchioles, the tiny air tubes in the lungs.
bronchitis [Medical_term]
Inflammation of the bronchi.
bronchospasm [Medical_term]
Contraction of the muscle in the walls of the bronchi.
bronze diabetes [Medical_term]
A disorder of iron metabolism resulting in iron pigment deposits in the skin and other body tissues that causes a change in skin color.
brucellosis [Medical_term]
An infection characterized by fluctuating fever, headache, anemia and vague physical discomfort that’s transmitted to humans from domesticated goats, pigs and cattle.
bruise [Medical_term]
Discoloration of the skin due to a buildup of blood in the underlying soft tissues. Also called a contusion.
bruxism [Medical_term]
Grinding of the teeth.
bubo [Medical_term]
A swollen, infected lymph node (especially in the groin). The node may enlarge enough that it begins to drain through the skin.
Buerger’s disease [Medical_term]
Blockage of medium-sized blood vessels in the hands and feet by clotting and inflammation. This process causes severe pain and may lead to gangrene.
bulimia [Medical_term]
An eating disorder characterized by binge eating followed by vomiting or use of laxatives. Usually caused by a variety of psychological reasons.
bunion [Medical_term]
Localized swelling of the big toe at its joint with the foot.
bursa [Medical_term]
A small, fluid-filled sac that allows one part of a joint to move freely over another part.
bursitis [Medical_term]
Inflammation of a bursa.

C

cachexia [Medical_term]
A generally weakened, emaciated condition of the body.
caffeine [Medical_term]
A bitter-tasting, water-soluble compound that acts as a central nervous system stimulant and has a mild diuretic (increasing urination) effect.
calciferol [Medical_term]
Vitamin D.
calcification [Medical_term]
Calcium salt deposits in soft tissues.
calculus [Medical_term]
A small, hard mass or stone formed in the body, as in a kidney or gallbladder, or a hard coating on the surface of the teeth.
callus [Medical_term]
1. Localized thickening of the skin. 2. A fibrous band formed around the site of a fracture that seals the ends of the bone together and is then gradually replaced by mature bone.
calorie [Medical_term]
The amount of energy needed to raise the temperature of one kilogram of water one degree. Commonly used to express the amount of energy-producing value in food.
Calve-Perthes [Medical_term]
A disease in children affecting the growth plate of the head of the thigh, caused by interference in the blood supply.
camphor [Medical_term]
An agent derived from a cinnamon tree that’s used to relieve pain and itching.
cancer [Medical_term]
Abnormal cells with uncontrolled cell growth.
Candida [Medical_term]
The class of yeast that causes thrush and vaginal yeast infections.
canker [Medical_term]
An open sore on the lip or skin inside the mouth.
Cannabis [Medical_term]
The class of plants that includes marijuana and other hemps.
capillary [Medical_term]
A small, blood-containing vessel connecting the veins and arteries.
carbohydrates [Medical_term]
A group of energy-storage molecules that includes sugars and starches. Carbohydrates contain four calories per gram.
carbon dioxide [Medical_term]
An odorless, colorless gas produced as the end product of aerobic respiration.
carbon monoxide [Medical_term]
An odorless, colorless, poisonous gas produced from the incomplete combustion of carbon. Prevents the blood from carrying oxygen.
carbuncle [Medical_term]
A hard, painful, pus-filled infection of the skin. Carbuncles are larger than boils and frequently have more than one opening.
carcinogen [Medical_term]
A cancer-causing substance.
carcinoma [Medical_term]
A cancerous tumor.
cardiac [Medical_term]
Having to do with the heart or, less commonly, the upper portion of the stomach.
cardiomegaly [Medical_term]
Enlargement of the heart.
cardiovascular [Medical_term]
Having to do with the heart and blood vessels.
caries [Medical_term]
Decay of the teeth or bone.
carotene [Medical_term]
The fat-soluble pigment in carrots, tomatoes and other vegetables, egg yolks, milk fat and other substances that can be converted in the body to vitamin A.
carotid [Medical_term]
The main artery in the neck.
Carpal [Medical_term]
Having to do with the wrist.
carpal tunnel syndrome [Medical_term]
Pain, numbness and tingling of the fingers caused by compression of the median nerve at the wrist.
carrier [Medical_term]
Someone who’s capable of transmitting a disease (especially an infectious or genetic disorder) to another person but who usually has no symptoms of the disease.
cartilage [Medical_term]
Elastic connective tissue on the joint surfaces of bone and some parts of the skeleton, including the nose and ears.
castor oil [Medical_term]
An oil extracted from the castor bean plant that’s irritating to the intestine and promotes bowel movements.
castration [Medical_term]
To remove the gonads, such as the testicles, making the male unable to have children.
cat-scratch fever [Medical_term]
A bacterial infection acquired through the scratch of a cat or other animal.
catalepsy [Medical_term]
A condition in which the body and limbs stay in the position in which they’re placed.
cataract [Medical_term]
An opaque area in the lens of the eye.
catheter [Medical_term]
A tube used to drain or inject fluids.
cauliflower ear [Medical_term]
A trauma-induced deformity of the ear caused by repeated cartilage and soft-tissue injury.
caustic [Medical_term]
A chemical that can cause burns.
cauterize [Medical_term]
To purposely burn with a hot instrument or caustic substance to destroy tissue, such as a wart.
cavity [Medical_term]
A hollow place or hole within the body.
CBC [Medical_term]
Complete blood cell count.
cecum [Medical_term]
The first part of the large intestine just below the small intestine or ileum.
celiac [Medical_term]
Having to do with the abdomen.
cell [Medical_term]
The basic unit of organization of all living organisms.
cellulitis [Medical_term]
Infection of the skin.
cellulose [Medical_term]
A complex carbohydrate. Cellulose is a source of dietary fiber because it can’t be digested.
cephalalgia [Medical_term]
Headache.
cerebellum [Medical_term]
The part of the brain that coordinates muscular movements.
cerebrum [Medical_term]
The main part of the brain.
cerumen [Medical_term]
Earwax.
cervical [Medical_term]
Having to do with the neck (cervical spine) or the cervix of the uterus.
cervix [Medical_term]
The neck-like portion of an organ, especially the part of the uterus that extends into the vagina.
cesarean section [Medical_term]
Delivery of a baby through an incision in the abdominal wall and uterus.
chalazion [Medical_term]
A chronic, small swelling on the rim of the eyelid.
chancre [Medical_term]
The painless ulcer of primary syphilis that appears on the genitals.
chancroid [Medical_term]
A sexually transmitted disease that causes soft, painful open sores in the genital area. Not syphilis. Characterized by swelling of the sebaceous glands, resulting in pimples on the face, back and chest.
charley horse [Medical_term]
Painful stiffness from muscular strain in an arm or leg.
cheilosis [Medical_term]
A condition in which cracks or sores occur at the corners of the mouth.
chickenpox [Medical_term]
A viral disease that usually begins with fever and cough, followed by a rash that progresses from red bumps to blisters to scabs. A vaccine is available to prevent this disease. Also called varicella or varicella zoster.
chilblain [Medical_term]
Painful redness of the fingers, toes or ears caused by exposure to cold.
childbed fever [Medical_term]
This is a severe illness marked by fever that’s caused by an infection in mothers after giving birth. Also called puerperal sepsis.
chill [Medical_term]
A cold sensation with shivering that sometimes occurs before a fever.
chiropractic [Medical_term]
An approach to health care based on the assumption that most diseases are caused by pressure on the nerves. This pressure is thought to be caused by faulty alignment of the bones that prevents the nerves from functioning properly.
Chlamydia [Medical_term]
A microorganism, Chlamydia trachomatis, that’s a frequent cause of sexually transmitted disease. It can also cause pneumonia and eye infections.
chloasma [Medical_term]
Dark coloring of the skin often seen during pregnancy and at menopause. Also occurs in Addison’s disease.
chlorination [Medical_term]
The addition of chlorine to kill harmful microorganisms in water or sewage.
cholecystitis [Medical_term]
Inflammation of the gallbladder.
cholera [Medical_term]
Watery diarrhea caused by drinking water or eating food that’s con-taminated with Vibrio cholere. The disease is spread through the stools of infected persons.
cholesteatoma [Medical_term]
A tumor-like mass that sometimes forms as a result of a chronic middle ear infection.
cholesterol [Medical_term]
A fat-like substance that, if present in the blood in large amounts, is associated with the development of heart disease.
chondritis [Medical_term]
Inflammation of the cartilage.
chondromalacia [Medical_term]
Softening of cartilage.
chorea [Medical_term]
A nervous system disorder characterized by involuntary spasms of the limbs or facial muscles. A hereditary form is called Huntington’s chorea.
chromosomes [Medical_term]
The DNA-containing cellular structures that carry genetic information.
chronic [Medical_term]
Persistent. Ongoing. Lasting a long time.
cilia [Medical_term]
Short, hair-like structures extending from certain cells.
circadian [Medical_term]
A repetitive pattern or fluctuation with a 24-hour cycle.
circulation [Medical_term]
The flow of blood through the body. Includes the heart, arteries, veins and capillaries.
circumcision [Medical_term]
Surgical removal of the foreskin of the penis.
cirrhosis [Medical_term]
Inflammatory disease of the liver characterized by scarring and shrinkage.
claudication [Medical_term]
Pain in the legs while walking that’s caused by blockage of the arteries.
claustrophobia [Medical_term]
Fear of closed spaces.
clavicle [Medical_term]
Collarbone.
clawhand [Medical_term]
A condition of the hand causing distorted fingers resulting from nerve injury.
cleft lip or palate [Medical_term]
A congenital split of the upper lip or roof of the mouth.
clitoris [Medical_term]
A small, sensitive erectile organ located in the female at the top of the vulva.
Clostridium [Medical_term]
A genus of bacteria that includes the agents capable of causing food poisoning and tetanus.
clot [Medical_term]
A jelly-like mass of blood.
clubfoot [Medical_term]
A deformity in which the foot is turned inward from its normal position.
coal tar [Medical_term]
A by-product of coal used in the treatment of some skin conditions, such as psoriasis.
cobalamin [Medical_term]
Vitamin B12.
cocaine [Medical_term]
A drug that is made from coca leaves. It can be used by a doctor as a topical anesthetic. It’s often abused for its euphoric affects. It’s highly addictive.
coccyx [Medical_term]
The tailbone.
cochlea [Medical_term]
The portion of the inner ear that senses sound.
coitus [Medical_term]
Sexual intercourse.
cold [Medical_term]
An upper respiratory infection.
cold sore [Medical_term]
Herpes simplex infection of the lip.
colic [Medical_term]
1. A sudden, spasmodic abdominal pain. 2. In infants, a pattern of excessive crying, apparent abdominal pain and irritability.
collagen [Medical_term]
A protein formed in the connective tissue of the body.
colon [Medical_term]
The large intestine.
Colorado tick fever [Medical_term]
A viral illness spread by ticks. Characterized by headache, backache and fever that begins to break and then returns midway through the course of the illness.
colostomy [Medical_term]
Surgery that makes an opening to the intestine through the surface of the abdomen. The opening empties the bowels.
colostrum [Medical_term]
An antibody-rich fluid released by the breasts for a short time after the birth of a baby, before the true milk is produced.
comedo [Medical_term]
A dark-topped plug of fatty material in the opening of a hair follicle. The color is the result of exposure of the fat to the air.
communicable disease [Medical_term]
A disease spread through direct contact with an infected person or substance.
compress [Medical_term]
A dressing used to apply pressure or medicine to an area. Useful in applying heat or cold.
compulsion [Medical_term]
An overwhelming urge to perform an act. Often used to describe ritual or repetitive behaviors.
conception [Medical_term]
Fertilization. The union of sperm and egg.
concussion [Medical_term]
A loss of consciousness because of a head injury.
condom [Medical_term]
A sheath worn over the penis or inside the vagina (female condom) during intercourse to protect against pregnancy and disease.
Cone [Medical_term]
The light-sensing structure on the retina of the eye capable of detecting color.
congenital [Medical_term]
Present at birth.
conjunctiva [Medical_term]
The membrane lining the eyelids and covering the eyeball.
conjunctivitis [Medical_term]
Inflammation of the conjunctiva. Also called pink eye.
connective tissue [Medical_term]
Fibrous tissue with a wide variety of connecting and supporting functions within and between body organs.
conscious [Medical_term]
Mentally awake and aware. Knowing what one is doing and why.
constipation [Medical_term]
A condition in which the stool becomes too hard for easy elimination.
consumption [Medical_term]
1. Using up. 2. Wasting of the body; especially used in reference to advanced tuberculosis.
contagious [Medical_term]
Easily transmitted by direct or indirect contact.
contraception [Medical_term]
The intentional prevention of conception or impregnation. Also called birth control.
contraction [Medical_term]
A shortening or increase in tension.
contracture [Medical_term]
Deformity caused by abnormal shortening of the muscles.
contrast medium [Medical_term]
A substance used in x-ray studies to aid in showing internal structures.
contusion [Medical_term]
Bruise.
convulsion [Medical_term]
A seizure.
cor pulmonale [Medical_term]
Increased blood pressure in the lungs, causing chest pain, shortness of breath, swelling in the feet and fluid in the lungs.
cornea [Medical_term]
The clear, external part of the eye.
corns [Medical_term]
A hardened area of skin on the foot caused by persistent friction or pressure.
coronary arteries [Medical_term]
The blood vessels encircling the heart that provide the heart muscle with oxygen.
corticosteroid hormones [Medical_term]
Hormones produced by the adrenal glands.
coryza [Medical_term]
Runny nose.
costochondritis [Medical_term]
Inflammation of the cartilage-containing joints where the ribs join the breastbone (sternum).
coxsackievirus [Medical_term]
A virus that can cause inflammation of the heart, brain or eye, or hand-foot-and-mouth disease.
cramp [Medical_term]
A painful muscle spasm.
craniotomy [Medical_term]
A surgical opening of the skull.
cranium [Medical_term]
The skull, or bony structure of the head, that protects the brain.
creatinine [Medical_term]
A substance formed from the making of creatine, an important nitrogen compound made in the body. Common in blood, urine and muscle tissue.
cretinism [Medical_term]
Physical and mental retardation due to congenital lack of thyroid hormone.
Crohn’s disease [Medical_term]
Chronic inflammation of the digestive tract, especially of the lower small intestine and colon.
croup [Medical_term]
Obstruction of the upper respiratory tract at or below the larynx (voice box), resulting in a hoarse, barking cough.
crowning [Medical_term]
The first appearance of a baby’s scalp during the birth process.
cryosurgery [Medical_term]
Destruction of tissue using extreme cold. A procedure used to treat skin lesions.
CT [Medical_term]
Computed tomographic scan.
culdocentesis [Medical_term]
A procedure to remove pus or blood from the abdomen through the vagina.
Cushing’s syndrome [Medical_term]
A disorder caused by overactivity of the pituitary gland.
cuspid [Medical_term]
A tooth with one point, or “canine” tooth.
cutaneous [Medical_term]
Having to do with the skin.
cyanosis [Medical_term]
Bluish discoloration of the skin caused by lack of oxygen in the blood.
cyst [Medical_term]
A sac or pocket in the body containing fluid or semisolid material.
cystitis [Medical_term]
Inflammation of the bladder.
cytology [Medical_term]
The study of cells.
cytomegalovirus [Medical_term]
A virus that infects cells and causes them to become enlarged. Babies infected with the virus develop mental and sensory disorders.

D

D and C [Medical_term]
Dilatation and curettage. A surgical procedure in which the uterine lining is removed by scraping.
dacryocystitis [Medical_term]
Inflammation of the sac that collects tears for drainage from the eye.
dandruff [Medical_term]
Little scales or flakes of dead skin on the scalp. Also called seborrheic dermatitis.
debridement [Medical_term]
Removal of foreign material or dead tissue.
decalcification [Medical_term]
Loss of calcium from the bones or teeth.
decidua [Medical_term]
The mucus lining of the uterus that’s passed after childbirth or during the menstrual period.
decubitus [Medical_term]
A skin ulcer or bedsore.
defibrillator [Medical_term]
A machine that delivers an electrical shock to an irregularly beating heart to restore normal rhythm.
degenerative joint disease [Medical_term]
A common form of arthritis in which tissue changes occur in one or more joints, such as swelling, lumps or cysts, or small pieces of loose bone and cartilage, which cause stiffness and pain. Also called osteoarthritis.
dehydration [Medical_term]
Excessive loss of body water resulting in weakness, dizziness and other symptoms. It can be life-threatening if not treated, especially in young children and babies.
delirium [Medical_term]
An abnormal mental state characterized by excitement and hallucinations.
deltoid [Medical_term]
The triangular muscle of the shoulder.
delusion [Medical_term]
A false belief.
dementia [Medical_term]
Progressive mental deterioration.
dentition [Medical_term]
Arrangement of the teeth.
dependence [Medical_term]
A state of absolute need, both physical and psychological.
depilatory [Medical_term]
A substance that temporarily removes hair from the skin.
depression [Medical_term]
Decreased functional activity. Sinking of spirits. Intense sadness, beyond what’s normally expected.
dermabrasion [Medical_term]
A procedure that removes scars, tattoos or other skin defects with fine sandpaper or a high-speed brush.
dermatitis [Medical_term]
Inflammation of the skin.
dermatology [Medical_term]
A medical specialty that deals with the skin.
desensitization [Medical_term]
Reducing or eliminating sensitivity to a particular substance.
desquamation [Medical_term]
The shedding of cells from the surface of the skin or mucous membranes.
devascularization [Medical_term]
Interruption of blood circulation to part of the body.
dextrose [Medical_term]
A simple sugar. Glucose.
diabetes insipidus [Medical_term]
Loss of water through the kidneys as a result of decreased production of the pituitary hormone vasopressin (an antidiuretic hormone).
diabetes mellitus [Medical_term]
A disorder of carbohydrate metabolism resulting from insulin deficiency. Characterized by high blood sugar levels that result in weakness, frequent urination and increased thirst and hunger.
diagnose [Medical_term]
To identify a disease.
diagnosis [Medical_term]
The process of identifying a disease or medical condition.
dialysis [Medical_term]
A treatment to remove certain molecules from the blood, particularly in people with kidney failure.
diaphoresis [Medical_term]
Excessive sweating.
diaphragm [Medical_term]
1. The dome-shaped respiratory muscle separating the chest from the abdomen. 2. A barrier contraceptive device molded to fit over the cervix.
diarrhea [Medical_term]
Production of feces in increased volume and with greater fluidity than normal.
diastole [Medical_term]
The relaxation phase of the heartbeat.
diastolic [Medical_term]
Diastolic blood pressure is the pressure when your heart relaxing between beats and filling with blood.
diet [Medical_term]
The total food consumed by an individual. A therapeutic diet is a prescription of required or restricted foods.
dietitian [Medical_term]
An expert who is trained in the use of diet and nutrition to maintain or restore health.
digestion [Medical_term]
The mechanical and chemical conversion of food into simpler compounds that can be absorbed by the body.
digit [Medical_term]
A finger or toe.
dilation [Medical_term]
The process of expanding or enlarging.
diphtheria [Medical_term]
An infectious disease of childhood characterized by fever, sore throat and the presence of “dirty” (white, gray, brown) membranes in the throat.
diplopia [Medical_term]
Double vision.
discoid lupus erythematosus [Medical_term]
A round, red, scaling rash on the nose, forehead, cheeks, scalp or other areas of the body. It may be associated with systemic lupus erythematosus.
disinfectant [Medical_term]
A chemical agent used to destroy microorganisms on inanimate objects.
disk [Medical_term]
A round, flat structure, particularly the fibrous cartilage layer between two vertebrae (the bones that make up the spine). Also called intervertebral disk.
diskectomy [Medical_term]
Removal of an intervertebral disk of the spine.
dislocation [Medical_term]
Displacement of a bone from a joint.
disorientation [Medical_term]
Mental confusion, especially of time, place or person.
distal [Medical_term]
A location farther from a point of reference. For example, the foot is distal to the knee, relative to the center of the body.
diuresis [Medical_term]
Increased elimination of urine.
diverticula [Medical_term]
Pouches or sacs opening out from a main cavity or tubular organ of the body.
diverticulitis [Medical_term]
Inflammation of small pouches that may form on the wall of the colon.
diverticulosis [Medical_term]
A condition in which pouches form on the wall of the colon.
dorsal [Medical_term]
Toward the back.
douche [Medical_term]
A flow of liquid or vapor directed onto or into a part of the body.
Down syndrome [Medical_term]
A genetic disorder characterized by some degree of mental retardation and by various physical malformations, such as slanted eyes and a broad face.
DPT [Medical_term]
A vaccine containing antigens from diphtheria, pertussis and tetanus.
dressing [Medical_term]
A bandage for an external wound.
dropsy [Medical_term]
Abnormal buildup of fluid in tissues or a body cavity.
duct [Medical_term]
A channel or passage through which fluids move.
duodenal [Medical_term]
Having to do with the duodenum.
duodenum [Medical_term]
The first part of the small intestine that begins at the stomach and is the entry point for the pancreatic and common bile duct.
Dupuytren’s contracture [Medical_term]
Scarring of the palmar ligament in the hand, causing progressive curling of one or more fingers and a thickening of the palm.
dwarfism [Medical_term]
A deficiency of growth hormone resulting in short stature.
dysentery [Medical_term]
Infection of the intestine resulting in severe diarrhea and cramps, frequently associated with blood or mucus in the stools.
dysmenorrhea [Medical_term]
Painful menstruation.
dyspepsia [Medical_term]
Indigestion.
dysphagia [Medical_term]
Difficulty swallowing.
dyspnea [Medical_term]
Labored breathing.

E

eardrum [Medical_term]
The tympanic membrane that’s visible in the ear. It vibrates in response to sound waves.
ecchymosis [Medical_term]
A collection of blood in the tissues causing a black and blue, or yellow, area.
ECG [Medical_term]
Electrocardiogram.
eclampsia [Medical_term]
An attack of convulsions. Particularly used to describe toxemia (toxins in the blood) of pregnancy.
ectopic pregnancy [Medical_term]
When the fertilized egg is implanted and develops outside of the uterus.
ectropion [Medical_term]
An outward turning of the eyelid.
eczema [Medical_term]
A rash characterized by itching, scaling, swelling and oozing. A common allergic reaction.
edema [Medical_term]
Buildup of excessive fluid around the cells in the body.
EEG [Medical_term]
Electroencephalogram.
effacement [Medical_term]
Thinning of the cervix during labor.
effusion [Medical_term]
Buildup of fluid in a part of the body, particularly a joint.
ejaculation [Medical_term]
The sudden ejection of semen from the male body. Climax.
EKG [Medical_term]
Electrocardiogram.
electroconvulsive [Medical_term]
A type of therapy used to treat severe, unresponsive depression by passing electrical current through the brain.
electrolysis [Medical_term]
Destruction of tissue through the use of electricity; often used to permanently remove unwanted hair from the body.
electrolytes [Medical_term]
Compounds that separate into charged particles in water. The main electrolytes in the human body are sodium, potassium, bicarbonate, chloride, magnesium, calcium and phosphate.
elephantiasis [Medical_term]
A chronic disease characterized by the enlargement of certain parts of the body and by the hardening and ulceration of the surrounding skin. It is often caused by an infestation of a worm called a filarial worm.
embolism [Medical_term]
The obstruction of a blood vessel by a clot or mass of foreign material.
emesis [Medical_term]
Ejecting the contents of the stomach through the mouth.
emphysema [Medical_term]
Chronic lung disease characterized by loss of elasticity of lung tissue and resulting in trapped air in the lung.
empyema [Medical_term]
Buildup of pus in a cavity of the body.
encephalitis [Medical_term]
A serious infection resulting in inflammation of the brain.
encopresis [Medical_term]
Fecal incontinence. Inability to hold feces.
endocarditis [Medical_term]
Inflammation or infection of the inside of the heart, often including the heart valves.
endocrine glands [Medical_term]
Glands that are ductless and release their secretions directly into the bloodstream.
endometriosis [Medical_term]
A condition in which cells from the lining of the uterus are found in other locations within the pelvic cavity. This condition frequently causes pelvic pain and menstrual difficulties.
enema [Medical_term]
1. Introduction of fluid into the rectum to bring about a bowel movement. 2. The solution introduced into the rectum to bring about a bowel movement.
ENT [Medical_term]
The medical specialty of the ear, nose and throat.
enteritis [Medical_term]
An inflammation of the intestines that usually causes cramps and diarrhea.
enuresis [Medical_term]
Bedwetting.
eosinophil [Medical_term]
A type of white blood cell that becomes more abundant in the bloodstream in certain parasitic and allergic conditions.
epidemiology [Medical_term]
The study of the causes and control of diseases in human populations.
epidermis [Medical_term]
The outermost layer of skin.
epididymis [Medical_term]
The elongated structure behind each testicle where sperm are stored.
epiglottis [Medical_term]
The flap of cartilage at the base of the tongue that closes the trachea during swallowing to keep food or liquids from entering the airway.
epilepsy [Medical_term]
A disorder of the central nervous system that causes convulsions, or seizures.
epinephrine [Medical_term]
Adrenaline, a hormone produced in the core of the adrenal glands that’s sometimes used to treat asthma and allergic reactions.
episiotomy [Medical_term]
An incision of the perineum (the area between the vagina and anus in women), often performed during labor to minimize trauma to the perineum during the delivery of a baby.
epistaxis [Medical_term]
Nosebleed.
epithelium [Medical_term]
The layer of cells covering internal and external surfaces of the body.
erysipelas [Medical_term]
A febrile (fever-associated) skin infection caused by a group A hemolytic streptococci.
erythema [Medical_term]
Redness of the skin.
erythema infectiosum [Medical_term]
A viral infection most common in children that begins with a red, warm rash on the face, along with some paleness around the mouth. Also called Fifth disease.
erythema multiforme [Medical_term]
An eruption of flat or raised spots of skin as a result of hypersensitivity to certain drugs or allergies.
erythema nodosum [Medical_term]
The sudden appearance of tender raised nodes on the lower limbs as a result of an infection, hypersensitivity to certain drugs or other conditions.
erythrocyte [Medical_term]
Red blood cell.
Escherichia coli [Medical_term]
A type of common bacteria normally found in the colon. Some strains that cause diarrhea are acquired during travel.
esophagitis [Medical_term]
Inflammation of the esophagus, often caused from a reflux of acid from the stomach.
esophagus [Medical_term]
The tube through which food passes from the pharynx to the stomach.
estrogen [Medical_term]
Female sex hormone.
eustachian tube [Medical_term]
The narrow tube connecting the nose and middle ear to allow air pressure in the middle ear to equalize with the outside environment.
exacerbate [Medical_term]
Cause something to increase in severity. To make more intense, irritate.
exanthem [Medical_term]
Skin rash.
excise [Medical_term]
To remove by cutting.
exocrine glands [Medical_term]
Glands that secrete chemicals externally, either through a tube or duct.
expectorant [Medical_term]
A substance that loosens mucus so it’s more easily cleared from the respiratory passages.

F

faint [Medical_term]
Temporary loss of consciousness because of an insufficient blood supply to the brain.
fallopian tube [Medical_term]
The tubal passageway connecting the ovary to the uterus.
familial cholesterolemia [Medical_term]
An inherited disorder causing abnormally high levels of cholesterol in the blood.
fascia [Medical_term]
Fibrous sheets of tissue connecting or covering the muscles.
fat [Medical_term]
A major energy source for animals and humans. Fat contains nine calories per gram.
fatigue [Medical_term]
Physical or mental exhaustion. Weariness.
feces [Medical_term]
Body waste expelled from the rectum. Also called bowel movement or stool.
femoral [Medical_term]
Having to do with the femur.
femur [Medical_term]
The thigh bone.
fertility [Medical_term]
The ability to have children.
fertilization [Medical_term]
The process of joining the male’s sperm and the female’s ovum (egg).
fetal [Medical_term]
Having to do with the fetus.
fetus [Medical_term]
The unborn baby from the end of the eighth week after fertilization of the egg to birth.
fever [Medical_term]
Abnormally high body temperature.
fiber [Medical_term]
1. A slender, thread-like structure of organ tissue. 2. In the diet, strands of complex carbohydrates (cellulose) that aren’t digestible.
fibrillation [Medical_term]
A rapid, uncoordinated series of contractions of some part of the heart muscle causing irregular heartbeats. Atrial fibrillation is the rapid, ineffective beating of the upper part of the heart. Ventricular fibrillation is the lethal rapid, ineffective beating of the lower part of the heart.
fibrin [Medical_term]
A serum protein that’s essential for the clotting process.
fibroid [Medical_term]
A noncancerous tumor of the uterus composed of muscle fibers. Also called uterine myoma.
fibromyalgia [Medical_term]
A painful condition with multiple sensitive areas, called “tender points,” affecting fibrous tissues, muscles, tendons and ligaments.
fibrositis [Medical_term]
Inflammation of fibrous tissues.
fibula [Medical_term]
The long, thin, outer bone of the lower leg.
fissure [Medical_term]
A narrow slit.
fistula [Medical_term]
An abnormal passage from an abscess, cavity or hollow organ to the skin or another abscess.
flaccid [Medical_term]
Soft and flabby. Often used to describe complete paralysis (loss of movement) without muscle spasm.
flatfoot [Medical_term]
A condition in which the normal arch of the foot is absent.
flatulence [Medical_term]
Excessive production of gas in the intestines or stomach.
fluorescein [Medical_term]
A compound used as a diagnostic aid to show injuries of the cornea or retina of the eye.
folic acid [Medical_term]
Folacin. One of the B-group vitamins essential for forming red blood cells.
folliculitis [Medical_term]
Inflammation of the hair follicles.
fontanelle [Medical_term]
A soft spot in the skull of an infant formed by the normal separation between the bony plates of the skull.
foreskin [Medical_term]
A loose fold of skin covering the tip of the penis.
fracture [Medical_term]
Broken, especially a broken bone.
fraternal twins [Medical_term]
Twins formed from two separate eggs that were fertilized at the same time. They may be the same or different genders and they have different genetic makeups. Also called dizygotic twins.
frenulum [Medical_term]
A fold of skin or mucous membrane that limits the movement of a body part. For example, the frenulum linguae is the midline fold under the tongue that attaches it to the floor of the mouth.
frigidity [Medical_term]
An inability to be sexually aroused.
fructose [Medical_term]
Fruit sugar.
fungus [Medical_term]
A group of organisms that includes yeasts, molds and mushrooms.

G

galactorrhea [Medical_term]
Excessive production of breast milk.
galactosemia [Medical_term]
A disease present at birth caused by a genetic lack of an enzyme needed to metabolize galactose into glucose. May result in mental retardation, cataracts and liver damage.
gall [Medical_term]
The bile produced in the liver and stored in the gallbladder.
gallbladder [Medical_term]
The storage sac for bile, located below the liver.
gallstone [Medical_term]
A stone-like mass that forms in the gallbladder.
gamma globulin [Medical_term]
Blood protein that contains most antibodies. Used in the temporary prevention of hepatitis and as treatment for disorders with antibody deficiencies.
ganglion cyst [Medical_term]
A benign, knot-like, cystic tumor on a tendon sheath.
gangrene [Medical_term]
The decay of body tissue in a part of the body where the blood supply is obstructed by injury or disease.
gastric [Medical_term]
Having to do with the stomach.
gastritis [Medical_term]
Inflammation of the stomach lining.
gastroenteritis [Medical_term]
Inflammation of the stomach and the intestines, usually producing symptoms of nausea, vomiting and diarrhea.
gastrointestinal [Medical_term]
Having to do with the stomach and intestines.
gene [Medical_term]
A unit of heredity located on a chromosome.
generic [Medical_term]
1. General; typical; not specific. 2. Medicine that’s not a name brand.
genetic [Medical_term]
Hereditary. Having to do with the genes.
genitalia [Medical_term]
The reproductive organs.
genitourinary system [Medical_term]
The genitals and urinary organs.
geriatrics [Medical_term]
The branch of medicine devoted to the elderly.
germ [Medical_term]
A disease-causing microorganism.
German measles [Medical_term]
A mild childhood disease that causes fever and rash. Although rubella is mild in childhood, it’s dangerous to pregnant women because it can cause birth defects. Also called rubella.
gestation [Medical_term]
The period of development within the uterus from conception to birth.
giantism [Medical_term]
Abnormal growth of the body due to an excessive amount of growth hormone produced by the pituitary gland.
giardiasis [Medical_term]
A diarrheal illness caused by infection with Giardia lamblia, a parasitic protozoan.
gingiva [Medical_term]
The gums.
gingivitis [Medical_term]
Inflammation of the gums.
gland [Medical_term]
An organ that releases a chemical. Endocrine glands are ductless and secrete hormones directly into the bloodstream. Exocrine glands secrete externally, either through a tube or duct.
glaucoma [Medical_term]
An eye disease, characterized by increased pressure within the eye, that can result in blindness if not treated.
glomerulonephritis [Medical_term]
When the filtering units in the kidneys, called the glomeruli, are damaged, the kidneys don’t function properly and waste and extra fluids build up in the body.
glossitis [Medical_term]
Inflammation of the tongue.
glucose [Medical_term]
Dextrose. A simple six-carbon sugar naturally found in fruits, honey and blood.
goiter [Medical_term]
Enlargement of the thyroid gland.
gonad [Medical_term]
A sex gland (ovary or testis).
gonorrhea [Medical_term]
A highly contagious, sexually transmitted bacterial disease of the genital/urinary system.
gout [Medical_term]
A form of arthritis caused by deposits of uric acid crystals in the joints, usually the feet, hands and, especially, the big toe.
graft [Medical_term]
A piece of skin or other tissue used as a transplant.
Gram’s stain [Medical_term]
A stain used as the first step in identifying bacteria.
grand mal [Medical_term]
A major epileptic seizure characterized by convulsions, unconsciousness and sometimes loss of urinary or bowel continence. Usually followed by a brief period of lethargy and disorientation.
Graves’ disease [Medical_term]
Overactive thyroid gland function (hyperthyroidism). Sometimes associated with protrusion of the eyes.
groin [Medical_term]
The region of the body where the thigh and lower abdomen meet.
Guillain-Barre syndrome [Medical_term]
A rare but reversible reaction to a viral illness or immunization that causes partial to complete loss of movement of certain muscles, weakness, numbness and tingling. In the severe form, a person may need intensive care and breathing support.
gynecology [Medical_term]
The branch of medicine that deals with the study and treatment of reproductive diseases in women.
gynecomastia [Medical_term]
Overdevelopment of male breast tissue. Usually benign and temporary.

H

halitosis [Medical_term]
Bad breath.
hallucination [Medical_term]
The sensory perception of sights, sounds or objects that don’t really exist.
hammer [Medical_term]
The malleus, a hammer-shaped bone in the middle ear.
hamstring [Medical_term]
The tendon located in the back of the knee and lower thigh.
hand-foot-and-mouth disease [Medical_term]
A viral infection characterized by a blister-like rash of the hands, feet and mouth.
hangnail [Medical_term]
A loose piece of skin at one side of a fingernail.
Hansen’s disease [Medical_term]
Leprosy.
harelip [Medical_term]
Cleft lip or palate.
Hashimoto’s thyroiditis [Medical_term]
A degenerative autoimmune disease of the thyroid gland that ultimately results in a marked reduction in the amount of thyroid hormone produced.
hay fever [Medical_term]
Allergic sensitivity to certain mold spores and pollens. Allergic reaction includes sneezing, itchy eyes, sore throat and runny nose.
heart [Medical_term]
The hollow, muscular organ responsible for pumping blood through the circulatory system.
heart block [Medical_term]
A condition in which electrical impulses aren’t properly transmitted from the heart’s upper to the lower chambers.
heart failure [Medical_term]
Inability of the heart to adequately pump blood.
heartburn [Medical_term]
Indigestion. A burning sensation in the chest caused by a reflux of acid into the esophagus or too much acid in the stomach.
heat exhaustion [Medical_term]
Headache, profuse sweating, weakness, muscle cramps, nausea and vomiting caused by excessive exposure to heat.
heat stroke [Medical_term]
A serious failure of the body’s heat-regulating mechanism resulting from excessive exposure to intense heat. Also called sunstroke.
hemangioma [Medical_term]
A tumor or swelling that’s composed of blood vessels.
hematemesis [Medical_term]
The vomiting of blood.
hematology [Medical_term]
The branch of medicine that pertains to blood and the organs involved in forming blood.
hematoma [Medical_term]
A tumor-like mass of coagulated blood in the soft tissues. A contusion or bruise.
hematuria [Medical_term]
The presence of blood in the urine.
hemiplegia [Medical_term]
Paralysis (loss of feeling or movement) of one side of the body.
hemochromatosis [Medical_term]
A disorder of iron metabolism characterized by excessive amounts of iron in the skin, liver and other tissues.
hemoglobin [Medical_term]
The oxygen-carrying molecule in red blood cells.
hemolysis [Medical_term]
The destruction of red blood cells.
hemophilia [Medical_term]
An inherited disorder, nearly always in males, in which one of the normal blood-clotting factors is deficient.
hemoptysis [Medical_term]
A cough that produces blood.
hemorrhage [Medical_term]
Severe bleeding, usually from damage to a blood vessel.
hemorrhoid [Medical_term]
An enlarged vein inside or just outside the rectum.
hemostasis [Medical_term]
Control of bleeding.
hepatic [Medical_term]
Having to do with the liver.
hepatitis [Medical_term]
Inflammation or infection of the liver.
heredity [Medical_term]
Transmission of genetic traits from parents to children.
hermaphrodite [Medical_term]
A person with both male and female sex organs.
hernia [Medical_term]
An abnormal protrusion of part of an organ through an abnormal opening.
herpes [Medical_term]
A recurring viral skin infection characterized by clusters of small blisters. Typically, sores are located near the mouth (fever blisters or cold sores) or in the genital region (genital herpes).
heterosexual [Medical_term]
Having to do with the opposite sex.
hexachlorophene [Medical_term]
A detergent that kills germs.
hiccup [Medical_term]
A sudden, involuntary spasm of the diaphragm. The sound of hiccups is caused by the sudden intake of air.
hidradenitis [Medical_term]
Inflammation of the sweat glands.
hip [Medical_term]
The part of the body surrounding the joint between the femur and pelvic bones.
hirsutism [Medical_term]
Excessive hair growth, usually on the face and chest. Often caused by an imbalance in hormones.
histamine [Medical_term]
A substance released from certain cells in response to allergens, associated with the development of allergic symptoms, including itchy eyes, sneezing and congestion.
histoplasmosis [Medical_term]
A fungal disease caused by inhaling the spores of Histoplasma capsulatum.
HIV [Medical_term]
Human immunodeficiency virus. A virus that slowly destroys the immune system. The virus that causes AIDS.
hives [Medical_term]
A skin reaction characterized by swelling, itching and burning.
Hodgkin’s disease [Medical_term]
A progressive form of lymphoma usually characterized by weakness, swollen lymph nodes, sweating, fever and weight loss.
homeopathy [Medical_term]
Medical treatment based on the theory that certain diseases can be cured by giving very small doses of substances that, in a healthy person, would produce symptoms like those of the disease.
homogenize [Medical_term]
To make more uniform in quality or consistency.
homosexual [Medical_term]
Having to do with the same sex.
hordeolum [Medical_term]
Inflammation of a gland on the eyelid. Also called a stye.
hormone [Medical_term]
A substance formed in an organ of the body and carried by body fluids to another organ or tissue, where it has a specific effect.
host [Medical_term]
An organism that harbors and provides sustenance for another organism.
housemaid’s knee [Medical_term]
Swelling just below the kneecap, caused by the buildup of fluid in response to the constant pressure of kneeling.
humerus [Medical_term]
The bone in the upper arm.
humidifier [Medical_term]
A device for adding moisture to the air.
Huntington’s chorea [Medical_term]
A hereditary form of chorea (sudden, jerky motions of the arms or other parts of the body) that usually affects people during their early 40s.
hydatid [Medical_term]
A cyst containing watery fluid and the larvae of certain tapeworms.
hydatid disease [Medical_term]
Infection with the larvae (cysts) of certain tapeworms.
hydatidiform mole [Medical_term]
A cystic tumor of the placental tissues of an abnormal pregnancy. Complications of this disorder include bleeding and infection.
hydrocele [Medical_term]
A painless swelling of the scrotum caused by the buildup of fluid in the outer covering of the testes.
hydrocephalus [Medical_term]
An enlargement of the head caused by the buildup of fluid within the ventricles of the brain. Also called “water on the brain.”
hygiene [Medical_term]
The science of health and its maintenance.
hymen [Medical_term]
The membrane partly or completely closing the opening to the vagina.
hyperbaric [Medical_term]
Characterized by greater-than-normal pressure. Hyperbaric oxygen is a therapeutic treatment designed to increase blood oxygen by delivering oxygen in a chamber room with greater-than-normal pressure.
hyperemesis gravidarum [Medical_term]
Excessive morning sickness.
hyperglycemic [Medical_term]
High blood sugar.
hyperparathyroidism [Medical_term]
A condition caused by the overexcretion of parathyroid hormone resulting in changes in the bone and an elevated level of calcium in the blood.
hypertension [Medical_term]
Abnormally high blood pressure.
hyperthyroidism [Medical_term]
Overproduction of thyroid hormone.
hyperventilation [Medical_term]
Rapid or deep breathing producing faintness, numbness, chest pain, apprehension and tingling, and spasms of the extremities.
hypnosis [Medical_term]
A sleep-like state induced by the suggestions of a hypnotist.
hypnotic [Medical_term]
1. Having to do with hypnosis. 2. Causing sleep.
hypochondriac [Medical_term]
Abnormal anxiety about one’s health, often to the point of believing one is suffering from a serious disease.
hypodermic [Medical_term]
Beneath the skin.
hypoglycemia [Medical_term]
Low blood sugar.
hypoparathyroidism [Medical_term]
Parathyroid hormone insufficiency due to lack of secretion of the parathyroid gland.
hypopituitarism [Medical_term]
Deficient activity of the pituitary gland causing slowed growth in children, fatigue and decreased appetite in adults, and cessation of menstrual periods in women.
hyposensitization [Medical_term]
To treat with frequent, small injections of an antigen to decrease the symptoms of an allergy to that antigen. Also called desensitization.
hypospadias [Medical_term]
An abnormal opening of the urethra on the underside of the penis or into the vagina.
hypothalamus [Medical_term]
The portion of the brain responsible for temperature regulation and control of the pituitary gland.
hypothermia [Medical_term]
Low body temperature.
hypothyroidism [Medical_term]
A condition of low thyroid hormone production resulting in weight gain, hair loss, sluggishness and thickening of the skin.
hypoxia [Medical_term]
An abnormal condition resulting from decreased availability of oxygen in the body tissues.
hysterectomy [Medical_term]
Surgical removal of all or part of the uterus.
hysteria [Medical_term]
1. Wild, uncontrolled excitement or other feelings. 2. A disorder in which anxiety is converted into physical symptoms that have no physical basis.

I

iatrogenic [Medical_term]
Resulting from medical treatment.
ichthyosis [Medical_term]
An inherited skin disorder that produces dry, rough, scaly skin.
identical twins [Medical_term]
Twins formed from a single egg. They are of the same gender and have the same genetic makeup. Also called monozygotic twins.
idiopathic [Medical_term]
Without a known cause.
ileitis [Medical_term]
Inflammation of the lower part of the small intestine.
ileum [Medical_term]
The lower part of the small intestine.
ileus [Medical_term]
Lack of movement of digested food and juices through the gastrointestinal tract. May be due to a blockage of the intestine.
ilium [Medical_term]
The flared portion of the pelvis. The hip bone.
IM [Medical_term]
Intramuscular.
immune [Medical_term]
Resistant to a particular disease.
immunity [Medical_term]
Resistance of the body to infection.
immunization [Medical_term]
The process of making an individual immune by vaccination or inoculation.
immunoglobulin [Medical_term]
A serum protein involved in immunity. An antibody.
impetigo [Medical_term]
Skin infection characterized by erupting sores. Caused by staphylococcus or streptococcus bacteria.
impotence [Medical_term]
Inability of a male to achieve erection and orgasm.
in situ [Medical_term]
In its original place. Carcinoma in situ means cancer that hasn’t spread to other locations.
incision [Medical_term]
A cut.
incisor [Medical_term]
Any of the front four teeth on either the upper or lower jaw.
incompetent [Medical_term]
1. Unable to make rational decisions. 2. Not functioning properly.
incontinence [Medical_term]
Inability to hold urine or feces.
incubate [Medical_term]
To provide the proper conditions for growth.
indigestion [Medical_term]
Upper abdominal discomfort usually experienced after a meal due to incomplete digestion.
induration [Medical_term]
The process of hardening. An abnormally hard spot.
infarct [Medical_term]
An area of dead or dying tissue produced by lack of blood flow to or from that area. For example, myocardial infarction is the death of heart muscle.
infection [Medical_term]
Causing disease, especially by the presence of foreign microorganisms in the body, including bacteria, viruses or parasites.
infectious disease [Medical_term]
A disease that can be spread from one person to another.
infertility [Medical_term]
Inability to produce children.
inflammation [Medical_term]
Swelling, redness, warmth and pain. A body tissue’s protective response to injury.
influenza [Medical_term]
A contagious and infectious respiratory illness usually occurring in the winter.
ingrown nail [Medical_term]
Edges of the nail become trapped under the skin, causing inflammation and, sometimes, infection.
injection [Medical_term]
A fluid introduced into the body by a syringe and needle.
innate [Medical_term]
Inborn, hereditary.
inoculation [Medical_term]
The injection of a disease agent into the body to cause a mild form of the disease and build immunity.
inoperable [Medical_term]
Not curable through surgery.
insanity [Medical_term]
Any form or degree of mental disturbance or unsoundness of mind, permanent or temporary, that makes a person incapable of rational conduct or judgment.
insemination [Medical_term]
To deposit sperm in the vagina.
insomnia [Medical_term]
An inability to fall asleep or to remain asleep.
insulin [Medical_term]
The hormone produced by the pancreas for regulating carbohydrate metabolism. Used in the treatment of diabetes mellitus.
integument [Medical_term]
Skin.
intercourse [Medical_term]
The exchange of communication between individuals. Sexual intercourse is the sexual joining of two people; coitus.
intestine [Medical_term]
The tube involved in digestion and extending from the stomach to the anus. Consists of the small intestine and the large intestine.
intoxication [Medical_term]
Poisoning, or the state of being affected by a poisonous substance. Often used to describe drunkenness.
intracellular [Medical_term]
Within a cell.
intradermal [Medical_term]
Within the skin.
intramuscular [Medical_term]
Within the muscle.
intrauterine [Medical_term]
Within the womb.
intravenous [Medical_term]
Within a vein. Intravenous infusion means to direct fluids through a needle or catheter directly into a vein.
intussusception [Medical_term]
Telescoping a section of the intestine into an adjoining section.
iris [Medical_term]
The colored portion of the eye. It’s a muscle that controls the amount of light entering the pupil.
iritis [Medical_term]
Inflammation of the iris.
irrigation [Medical_term]
Washing of a body cavity or wound with a stream of water.
ischemia [Medical_term]
A lack of blood supply to a body part.
IUD [Medical_term]
Intrauterine device. Used for contraception.
IV [Medical_term]
Intravenous.
IVP [Medical_term]
Intravenous pyelography.

J

jaundice [Medical_term]
Yellow discoloration of the skin and eyes caused by the buildup of bile in the blood.
jejunum [Medical_term]
The middle part of the small intestine, located between the duodenum and ileum.
joint [Medical_term]
The joining of two or more bones. In general, joints allow flexibility and mobility. However, some joints (for example, those in the skull) can’t move.
jugular [Medical_term]
Of the neck or throat, as in jugular veins.

K

Kaposi’s sarcoma [Medical_term]
Bluish-purple nodules of the skin that often bleed. These frequently occur in people who have AIDS.
keloid [Medical_term]
Excessive growth of scar tissue on the skin.
keratin [Medical_term]
The main protein of skin, hair and nails.
keratitis [Medical_term]
Inflammation of the cornea of the eye.
keratoconus [Medical_term]
A deformity of the cornea in which the cornea resembles the end of a football.
ketones [Medical_term]
The initial breakdown products of fatty acid metabolism. Unavailability of carbohydrates from starvation or uncontrolled diabetes mellitus increases the production of ketones. Too high a ketone level causes the blood chemistry to become acidic, a condition that’s potentially life-threatening.
kidney [Medical_term]
A pair of organs in the upper abdominal cavity that separate the body’s water and waste products from the blood and excrete them as urine through the bladder.
knee [Medical_term]
The complex hinge joint of the upper and lower leg involving the femur, tibia and patella.
knock-knee [Medical_term]
A deformity in which the knees rub together or touch each other in walking.

L

labia [Medical_term]
Lip-shaped structures; often used to describe the outer folds of the female genitalia.
labyrinth [Medical_term]
The system of interconnecting canals and cavities in the inner ear. Plays an important role in hearing and in balance.
laceration [Medical_term]
A wound caused by a cut from a sharp instrument or the tearing of body tissue.
lacrimation [Medical_term]
Discharge of tears. “Watering” eyes.
lactase [Medical_term]
An enzyme that converts the milk sugar lactose into glucose and galactose.
lactation [Medical_term]
Secretion of milk by the breasts.
lactose [Medical_term]
Milk sugar.
laryngitis [Medical_term]
Inflammation of the larynx, resulting in a temporary loss of voice.
larynx [Medical_term]
The voice box.
lateral [Medical_term]
Toward the side, sideways.
lavage [Medical_term]
Washing out of an organ, especially the stomach.
Legg-Calve-Perthes disease [Medical_term]
Perthes disease A disease in which the blood supply to the femur is reduced, causing the bone to collapse.
lens [Medical_term]
1. A curved glass used to bring together or spread rays of light. 2. The transparent organ lying behind the iris and pupil that focuses light on the retina of the eye.
leprosy [Medical_term]
A progressive infectious disease that attacks the skin, flesh and nerves; characterized by nodules, ulcers, scaly scabs, deformities and the eventual loss of sensation. Also called Hansen’s disease.
lesion [Medical_term]
Any damage to a tissue. Marks, spots, moles or other problems of the skin.
lethargy [Medical_term]
A lack of energy; sluggishness, dullness or apathy.
leukemia [Medical_term]
Cancer of the tissues in the bone marrow, spleen and lymph nodes.
leukocytes [Medical_term]
White blood cells, the blood cells responsible for fighting infection.
leukopenia [Medical_term]
A lower than normal number of leukocytes in the blood.
leukopheresis [Medical_term]
Selective removal of the white blood cells from a donor’s blood. The other components of the blood are then returned to the donor.
leukoplakia [Medical_term]
Thick, white patches in the mouth that may become malignant.
lichen [Medical_term]
Any of various skin diseases characterized by sores and enlarged skin markings.
ligament [Medical_term]
A tough band of connective tissue connecting bones or holding organs in place.
ligature [Medical_term]
A wire or thread used to tie off blood vessels or to close incisions or wounds.
lightening [Medical_term]
The feeling of decreased abdominal pressure during the last few weeks of pregnancy caused by the uterus dropping into the pelvis.
limbus [Medical_term]
Margin, or border. The margin of the cornea where it contacts the sclera.
lingua [Medical_term]
Tongue.
lipid [Medical_term]
Cholesterol, triglycerides and related substances.
lipocyte [Medical_term]
A fat cell.
lipolysis [Medical_term]
The splitting up, or destruction, of fat.
lipoma [Medical_term]
Fatty tumor.
lipoprotein [Medical_term]
Any of a group of proteins combined with a lipid that allow lipids to be transported in the circulatory system.
liposuction [Medical_term]
A surgical procedure that changes body shape by removing fat cells.
litholysis [Medical_term]
Breaking up of a stone, such as a gallstone.
lithotripsy [Medical_term]
A procedure to break up kidney stones into smaller pieces that can more easily pass out of the body.
liver [Medical_term]
The large organ in the upper right abdomen that functions in digestion and storage of food, disposal of worn-out red blood cells and detoxification of the body.
lobe [Medical_term]
1. The fleshy lower part of the ear. 2. A well-defined portion of an organ.
lobectomy [Medical_term]
Surgical removal of the lobe of an organ.
lobotomy [Medical_term]
A surgical operation in which a lobe of the brain, especially the frontal lobe of the cerebrum, is cut into or across. This used to be a common procedure to calm selected psychotic patients before the development of modern tranquilizers.
lochia [Medical_term]
The discharge from the vagina that occurs for several days to weeks after childbirth.
lockjaw [Medical_term]
Tetanus infection.
loins [Medical_term]
The portion of the back between the rib cage and pelvis.
lordosis [Medical_term]
Forward curvature of the spine, producing a hollow in the back.
LSD [Medical_term]
Lysergic acid diethylamide. A hallucinogenic drug.
lumbago [Medical_term]
Pain in the lower back.
lumbar [Medical_term]
Having to do with the lower back, the loins.
lungs [Medical_term]
The main respiratory organs in the chest where blood is oxygenated.
lupus erythematosus [Medical_term]
A usually chronic inflammatory disease that causes abnormalities of blood vessels and connective tissue in various parts of the body.
luteinizing hormone [Medical_term]
A hormone secreted by the anterior pituitary gland, responsible for stimulating ovulation in the female and testosterone production in the male.
Lyme disease [Medical_term]
A disease spread by deer ticks characterized at first by a skin rash, headache and fever, and later by arthritis and heart damage.
lymph [Medical_term]
Consists primarily of a clear, yellowish fluid and white blood cells. Found in the lymphatic system.
lymph node [Medical_term]
Any of many small, compact structures lying in groups along the course of the lymphatic vessels and producing lymphocytes.
lymphadenitis [Medical_term]
Inflammation of the lymph nodes.
lymphangitis [Medical_term]
Inflammation of a lymphatic vessel.
lymphatic system [Medical_term]
The vessels and structures involved in carrying lymph from the tissues to the blood.
lymphedema [Medical_term]
Swelling of tissue because of the buildup of too much lymph fluid.
lymphocyte [Medical_term]
A type of leukocyte (white blood cell) involved in the production of antibodies and the development of immunity.
lymphoma [Medical_term]
A malignant tumor of the lymphoid tissues.

M

macrophage [Medical_term]
A large cell that engulfs and digests foreign material.
macula [Medical_term]
The central part of the retina with the highest density of light receptors. Responsible for detailed vision.
macule [Medical_term]
A discolored, flat spot of skin.
malady [Medical_term]
Illness.
malaria [Medical_term]
An infectious disease of the tropics characterized by high fever and chills. The fever typically recurs every third day. Some forms of malaria can be fatal.
malignancy [Medical_term]
A tendency to worsen to a more serious illness or death. Commonly used to describe cancer.
malingering [Medical_term]
Deliberate exaggeration of the symptoms of an illness or injury for gain. For example, pretending to be ill in order to escape duty or work.
malleolus [Medical_term]
The rounded bony prominence on either side of the ankle.
malleus [Medical_term]
A small bone in the middle ear, often called the hammer.
malnutrition [Medical_term]
Poor nourishment resulting from an inadequate or improper diet.
malocclusion [Medical_term]
Improper meeting of the upper and lower teeth.
malunion [Medical_term]
Improper healing of the pieces of a broken bone.
mammary [Medical_term]
Having to do with the breast.
mandible [Medical_term]
The lower jaw.
mania [Medical_term]
A mental disorder. Characterized by extreme excitement and energy.
manic-depressive [Medical_term]
A mental disorder marked by alternating periods of excitability and depression. Also called bipolar affective disorder.
marijuana [Medical_term]
A drug derived from the leaves of the Cannabis sativa plant. Makes the user feel euphoric.
marrow [Medical_term]
The soft, sponge-like material inside the bones.
masculinization [Medical_term]
Development of male sex characteristics in a female.
masochism [Medical_term]
Pleasure from personal, psychological or physical pain.
mastectomy [Medical_term]
Surgical removal of the breast.
mastitis [Medical_term]
Inflammation of the breast.
mastoid [Medical_term]
A bony, rounded projection of the skull located behind each ear.
mastoiditis [Medical_term]
An infection of the mastoid bone that can cause redness, warmth, swelling and pain behind the ear, sometimes with drainage from the ear.
masturbation [Medical_term]
Sexual self-stimulation.
maxillae [Medical_term]
The pair of bones forming the upper jaw.
measles [Medical_term]
A highly contagious viral disease occurring most frequently in childhood and characterized by small, red spots on the skin, high fever and nasal discharge.
Meckel’s diverticulum [Medical_term]
A sac that may form in the small intestine, present at birth.
meconium [Medical_term]
The greenish fecal matter in a fetus, forming the first bowel movement of a newborn infant.
median nerve [Medical_term]
The nerve that stimulates some of the muscles of the hand and wrist.
mediastinum [Medical_term]
The tissues and organs located directly behind the sternum between the lungs. Contains the heart and its large vessels, the esophagus, thymus, lymph nodes and other structures and tissues.
medulla [Medical_term]
The inner part of an organ. The adrenal medulla is the center of the adrenal gland where epinephrine (adrenaline) is produced.
medulla oblongata [Medical_term]
The part of the brain just above the spinal cord that includes the control centers for breathing, circulation and heartbeat.
meibomian gland [Medical_term]
A type of gland of the eyelid’s inner surface. Inflammation of a meibomian gland can produce a swelling called a chalazion.
melancholia [Medical_term]
A mental state characterized by extreme sadness. A severe form of depression.
melanin [Medical_term]
A brownish-black pigment normally found in skin, hair and parts of the eye.
melanoma [Medical_term]
A dark-colored tumor, especially malignant melanoma, that is a form of skin cancer that can spread from one part of the body to another.
melasma [Medical_term]
Dark coloring of the skin often seen during pregnancy and at menopause. Also occurs in Addison’s disease.
melena [Medical_term]
Black-colored feces caused by the presence of blood.
membrane [Medical_term]
A thin layer of tissue covering an organ.
menarche [Medical_term]
A woman’s first menstrual period.
Meniere’s syndrome [Medical_term]
A disorder of the inner ear characterized by dizziness, ringing in the ears and progressive hearing loss.
meninges [Medical_term]
The three membranes covering the brain and spinal cord.
meningioma [Medical_term]
Tumor of the meninges, usually benign and slow-growing.
meningitis [Medical_term]
Inflammation of the meninges as the result of infection by bacteria or viruses. Symptoms include high fever, headache, stiff neck and vomiting. This is a life-threatening disease that must be treated promptly.
meniscus [Medical_term]
The cartilage in the knee joint.
menopause [Medical_term]
The time at which the menstrual cycle gradually stops. Sometimes referred to as the “change of life.”
menorrhagia [Medical_term]
Heavy bleeding during menstruation.
menstruation [Medical_term]
The periodic discharge of blood and tissues from the uterus. This usually occurs about every four weeks in a woman who isn’t pregnant. Also called “a period.”
metabolism [Medical_term]
The chemical and physical processes involved in building up, storing and using materials required for life.
metacarpal [Medical_term]
Any of the five bones that make up the hand and join the wrist to the fingers.
metaphysis [Medical_term]
The wider portion at the end of a long bone where growth occurs in infants and children.
metastasis [Medical_term]
The spread of a disease from its primary site in the body to another location in the body. Usually refers to cancer, but can be used to refer to infection.
metatarsal [Medical_term]
Any of the five bones of the foot directly jointed to each of the toes.
metra [Medical_term]
Uterus.
metritis [Medical_term]
Inflammation of the uterus.
metrorrhagia [Medical_term]
Uterine bleeding, usually of normal amount occurring at irregular intervals.
microbe [Medical_term]
A microorganism, such as bacterium.
microbiology [Medical_term]
The study of living microbes, including bacteria, protozoa and molds.
microencephaly [Medical_term]
Having an abnormally small brain.
microorganism [Medical_term]
A microscopic plant or animal.
midwife [Medical_term]
A person who helps women at childbirth, but who isn’t a nurse or physician.
migraine [Medical_term]
A group of symptoms that includes a severe headache, usually on one side of the head, and often accompanied by visual disturbances, nausea, irritability and other symptoms.
milia [Medical_term]
Pinhead-sized whitish skin lesions found on the face or trunk of some newborn infants.
miliaria [Medical_term]
Prickly heat or “heat rash” as a result of inflammation of the sweat glands and characterized by small, white or red skin eruptions.
miscarriage [Medical_term]
Natural loss of a fetus from the womb before it is sufficiently developed to survive. Also called spontaneous abortion.
mitral valve [Medical_term]
The valve of the heart between the left atrium and left ventricle that prevents the flow of blood back into the atrium when the heart muscle is contracting.
mittelschmerz [Medical_term]
Pelvic pain between periods, corresponding to the release of an ovum (egg) by an ovary.
mole [Medical_term]
1. A fleshy, pigmented skin blemish. 2. A mass of uterine tissue formed by a failure of the normal fertilization process during conception.
molluscum contagiosum [Medical_term]
A viral infection of the skin characterized by lesions with depressed centers containing a curd-like substance.
mongolism [Medical_term]
A condition present at birth characterized by mental deficiency, a broad face and slanting eyes. Also called Down syndrome.
monocyte [Medical_term]
A large white blood cell leukocyte.
mononucleosis [Medical_term]
An infection with Epstein-Barr virus. Also called “mono.”
morbid [Medical_term]
1. Pathologic or abnormal. 2. Having to do with, or characterized by, disease.
morning sickness [Medical_term]
Nausea and vomiting occurring during pregnancy.
MRI [Medical_term]
Magnetic resonance imaging.
mucosa [Medical_term]
The membrane covering canals and cavities that open on the outside of the body, such as the gastrointestinal tract and the respiratory tract. Also called mucous membrane.
mumps [Medical_term]
A viral disease of childhood characterized by swelling of the parotid (salivary) glands and fever.
murmur [Medical_term]
An extra heart sound that may be normal or abnormal.
muscle [Medical_term]
Tissue made up of bundles of long, slender cells that contract when stimulated.
mutation [Medical_term]
A damaged gene that may produce a disease or deficiency.
mute [Medical_term]
An inability or unwillingness to speak.
myalgia [Medical_term]
Muscle pain.
myasthenia gravis [Medical_term]
A chronic disease characterized by muscular weakness and fatigue.
myelin [Medical_term]
The fat-like substance that insulates certain nerve fibers.
myocarditis [Medical_term]
Inflammation of the heart muscle.
myoma [Medical_term]
A tumor of muscle cells.
myopia [Medical_term]
Nearsightedness.
myositis [Medical_term]
Inflammation of a muscle.
myringotomy [Medical_term]
An incision in the eardrum to relieve pressure or release fluid.

N

narcissistic [Medical_term]
Self-centered, being “in love” with oneself.
narcolepsy [Medical_term]
Frequent and uncontrolled desire for sleep.
nausea [Medical_term]
A feeling of sickness in the stomach, sometimes followed by the urge to vomit.
nebulizer [Medical_term]
A device that produces a very fine vapor to be inhaled.
necrosis [Medical_term]
Death of a cell or tissue.
nematode [Medical_term]
A roundworm that may infest the digestive tract of humans.
neoplasm [Medical_term]
A new growth, tumor.
nephrectomy [Medical_term]
Surgical removal of a kidney.
nephritis [Medical_term]
Inflammation of a kidney.
nephropathy [Medical_term]
Disease of the kidneys. Swelling or breakdown of the kidney.
nephrosis [Medical_term]
A disease of the kidney that causes malfunction but no inflammation. Also called nephrotic syndrome.
nerve [Medical_term]
A cord-like structure made up of special tissue for carrying electrical impulses from one part of the body to another.
neuralgia [Medical_term]
Pain along the course of a nerve.
neuritis [Medical_term]
Inflammation of a nerve.
neurofibromatosis [Medical_term]
An inherited disorder that causes dark spots on the skin and tumors of the skin, peripheral, optic and acoustic nerves.
neurology [Medical_term]
The branch of medicine that pertains to the nervous system.
neuroma [Medical_term]
A benign but sometimes painful tumor growing on a nerve.
neuron [Medical_term]
A nerve cell.
neuropathy [Medical_term]
Disease of the nervous system or of an individual nerve.
neurosis [Medical_term]
An emotional disorder that can interfere with a person’s ability to lead a normal life.
neutrophil [Medical_term]
A mature white blood cell with a three- to five-lobed nucleus.
nevus [Medical_term]
A mole or other colored spot on the skin.
nicotine [Medical_term]
A highly toxic and addictive component of tobacco. While the amounts obtained from smoking may not be enough to be immediately fatal, there’s a cause-and-effect relationship to heart disease.
night blindness [Medical_term]
A reduced ability to see in dim light. May be caused by a vitamin-A deficiency or glaucoma.
nit [Medical_term]
The egg of a louse.
nocturia [Medical_term]
Excessive urination at night.
node [Medical_term]
A swelling, knot or knob.
nonunion [Medical_term]
Failure of the ends of a broken bone to mend.
norepinephrine [Medical_term]
A hormone produced by the adrenal medulla and certain sympathetic nerve fibers.
nosocomial [Medical_term]
Having to do with the hospital. For example, an nosocomial infection is one that’s acquired during hospitalization.

O

obesity [Medical_term]
Having too much body fat. A weight more than 20% above the normal range.
obsession [Medical_term]
An ongoing preoccupation with an idea.
obsessive-compulsive [Medical_term]
Marked by a need to repeatedly perform certain behaviors or rituals.
obstetrics [Medical_term]
The branch of medicine that deals with the care and treatment of women during pregnancy and childbirth.
occiput [Medical_term]
The back of the head.
occult [Medical_term]
Hidden from view.
occupational illness [Medical_term]
Any illness caused or aggravated by a person’s job.
occupational therapy [Medical_term]
Teaching useful skills to sick or handicapped people to promote rehabilitation and healing.
ocular [Medical_term]
Having to do with the eye.
odontalgia [Medical_term]
Toothache.
olecranon [Medical_term]
The projection of the ulna (the larger of the two bones in the forearm) at the elbow.
olfactory [Medical_term]
Having to do with the sense of smell.
oligomenorrhea [Medical_term]
Light menstrual flow.
oligospermia [Medical_term]
A low number of sperm in the semen.
oliguria [Medical_term]
A condition characterized by an abnormally small output of urine.
oncology [Medical_term]
The study of tumors.
oophorectomy [Medical_term]
The surgical removal of an ovary.
ophthalmology [Medical_term]
The branch of medicine that pertains to the eye and its diseases.
optic neuritis [Medical_term]
Inflammation of the optic nerve, which connects the eye to the brain. Symptoms include pain with eye movement, blurred vision and sometimes temporary blindness.
optical [Medical_term]
Having to do with vision.
optometry [Medical_term]
The practice of eye and vision care.
orbit [Medical_term]
The bony cavity containing the eyeball. Eye socket.
orchiectomy [Medical_term]
The surgical removal of one or both testicles. Also called castration.
organ [Medical_term]
A structural unit of an animal or plant that serves a specific function.
organic [Medical_term]
Having to do with substances derived from living organisms.
orgasm [Medical_term]
Sexual climax.
orifice [Medical_term]
The entrance or outlet of a body cavity.
oropharynx [Medical_term]
The part of the pharynx behind the mouth and tongue.
orthodontics [Medical_term]
The branch of dentistry that deals with the correction of irregularities of the teeth and related facial problems.
orthopedics [Medical_term]
The branch of medicine that deals with the treatment of deformities, diseases and injuries of the bones, joints and muscles.
orthopnea [Medical_term]
Difficulty breathing when lying flat.
oscillation [Medical_term]
A back-and-forth motion; vibration.
Osgood-Schlatter disease [Medical_term]
Inflammation of the bone and cartilage of the shin bone, just below the knee.
ossicle [Medical_term]
A small bone.
osteoarthritis [Medical_term]
A slowly progressive form of arthritis, usually found in older people. Characterized by deterioration of bone cartilage.
osteoma [Medical_term]
A bony tumor.
osteomalacia [Medical_term]
Softening of the bones resulting from deficient bone calcium.
osteomyelitis [Medical_term]
Infection of a bone.
osteopathy [Medical_term]
A system of therapy emphasizing primary medical care and the importance of body mechanics and manipulation to correct abnormalities.
osteoporosis [Medical_term]
A bone disorder characterized by a reduction in bone density, chiefly found in women who have passed menopause and the elderly.
ostomy [Medical_term]
A procedure done to make a passageway for waste. A colostomy is an example.
otic [Medical_term]
Having to do with the ear.
otitis [Medical_term]
Inflammation of the ear. Otitis externa (inflammation of the ear canal) is also called swimmer’s ear, while otitis media is a middle-ear infection.
ovary [Medical_term]
The female sex gland that contains ova, or eggs.
ovulation [Medical_term]
The process in which an ovum is released from the ovary.
ovum [Medical_term]
Egg; the female reproductive element.
oximeter [Medical_term]
A device for determining the oxygen saturation level of the blood.
oxygen [Medical_term]
A chemical element essential for sustaining life.
oxytocin [Medical_term]
A pituitary hormone that encourages the pregnant uterus to contract and is sometimes used to induce labor. It also encourages milk to be expressed during breastfeeding.

P

Paget’s disease [Medical_term]
1. A type of cancer usually involving the breast’s larger ducts, areola and nipples. 2. A disease characterized by weakened and deformed bones.
palate [Medical_term]
The roof of the mouth.
palliative [Medical_term]
Controlling symptoms without curing the disease.
pallor [Medical_term]
Pale appearance of the skin.
palpate [Medical_term]
To feel with the fingers.
palpebra [Medical_term]
The eyelid.
palpitation [Medical_term]
A sensation that the heart is beating too rapidly or strongly.
palsy [Medical_term]
Inability to move parts of the body.
panacea [Medical_term]
A remedy for all diseases.
pancreas [Medical_term]
A gland located below and behind the stomach and liver that produces insulin and glucagon, the hormones involved in carbohydrate metabolism.
pancreatitis [Medical_term]
Inflammation of the pancreas.
pandemic [Medical_term]
A widespread epidemic.
panic [Medical_term]
A sudden attack of anxiety.
papilla [Medical_term]
A small nipple-shaped projection.
papilledema [Medical_term]
Swelling of the optic disk. May be due to an increase of pressure in the skull.
papilloma [Medical_term]
A benign tumor of the skin or mucous membranes. A wart.
papule [Medical_term]
A solid, raised skin lesion.
para-aminobenzoic acid [Medical_term]
PABA, a substance used in suntan lotion and used clinically to treat rickettsial diseases.
paracentesis [Medical_term]
Surgical removal of fluid from a cavity.
parainfluenza virus [Medical_term]
One of a group of viruses that cause a variety of upper respiratory diseases.
paralysis [Medical_term]
Inability to move parts of the body.
paranasal sinuses [Medical_term]
The mucosa-lined cavities in the bones of the skull that open into the passages of the nose.
paranoia [Medical_term]
A mental disorder characterized by a belief that others are out to get you.
paraplegia [Medical_term]
Inability to feel or move the legs.
parasite [Medical_term]
An organism that lives on or in the tissues of another organism and draws its nourishment from the host.
paraspadias [Medical_term]
A developmental abnormality in which the urethra opens along one side of the penis.
parathyroid glands [Medical_term]
Two pair of small glands situated next to or in the thyroid gland that are involved in the metabolism of calcium and phosphorus.
parenteral [Medical_term]
Inside the body, but outside the intestines.
paresis [Medical_term]
Partial or slight loss of feeling or movement.
paresthesia [Medical_term]
An abnormal sensation of burning or prickling on the skin, caused by a disorder of the nervous system.
Parkinson’s disease [Medical_term]
A progressive disease of the brain. Characterized by tremors and muscle stiffness.
parotid glands [Medical_term]
The largest of the salivary glands, located near the ears.
paroxysm [Medical_term]
A sudden attack, or raised level of intensity, of symptoms.
pasteurization [Medical_term]
Heating milk or other substances to a temperature of 140§F for 30 minutes to kill harmful bacteria.
patella [Medical_term]
The kneecap.
pathogen [Medical_term]
Any agent that causes disease.
pathology [Medical_term]
The study of changes caused by disease.
pectoral [Medical_term]
Having to do with the chest or breast.
pectus carinatum [Medical_term]
An abnormally prominent sternum or breastbone. Also called pigeon breast.
pectus excavatum [Medical_term]
A defect of the sternum that’s present at birth.
pedal [Medical_term]
Having to do with the feet.
pediatrics [Medical_term]
The branch of medicine that deals with the development and care of infants and children.
pediculosis [Medical_term]
Infestation with lice.
pelvis [Medical_term]
The bony structure formed by the sacrum, coccyx, ilium, pubis and ischium.
pemphigus [Medical_term]
A skin condition characterized by large blisters.
pepsin [Medical_term]
A digestive enzyme found in the stomach.
peptic [Medical_term]
Having to do with the stomach.
percutaneous [Medical_term]
Introduced through the skin.
perforation [Medical_term]
A hole or break through a membrane or the wall of an organ.
pericarditis [Medical_term]
Inflammation of the sac that surrounds the heart.
pericardium [Medical_term]
The fibrous sac the heart.
perineum [Medical_term]
The pelvic floor. In females, the region from the vagina to the anus. In males, the region from the base of the scrotum to the anus.
periodontitis [Medical_term]
Inflammation of the tissues around the teeth.
periosteum [Medical_term]
The connective tissue covering the bones of the body.
peripheral [Medical_term]
At or near the surface of the body. Located away from the center structure.
peristalsis [Medical_term]
The waves of contraction and relaxation of the smooth muscle of the digestive tract.
peritoneum [Medical_term]
The membrane lining the walls of the abdominal and pelvic cavity.
peritonitis [Medical_term]
Inflammation of the peritoneum.
pernicious [Medical_term]
Fatal.
pernicious anemia [Medical_term]
Anemia due to vitamin B12 deficiency.
pertussis [Medical_term]
A serious infectious respiratory disease of children. Named for the distinctive whooping sound made by the patient after a coughing spasm. Also called pertussis.
petit mal [Medical_term]
A mild seizure with a momentary loss of consciousness.
phagocyte [Medical_term]
Any cell that destroys invading microorganisms.
phagomania [Medical_term]
An obsession with eating.
pharmacist [Medical_term]
A person licensed to mix and dispense drugs.
pharyngitis [Medical_term]
Inflammation of the pharynx. Also called a sore throat.
pharynx [Medical_term]
The cavity of the canal leading from the mouth and nasal passages to the larynx and the esophagus.
phenylalanine [Medical_term]
An essential amino acid occurring in proteins. A small amount of phenylalanine is necessary in the diet to make the proteins that form human tissues.
phenylketonuria (PKU) [Medical_term]
A rare inherited disorder. Causes an inability to metabolize phenylalanine, an amino acid that’s a common part of many proteins that form tissues in the body. Left untreated, it causes severe mental retardation in infants.
phimosis [Medical_term]
Excessive tightness of the foreskin of the penis.
phlebitis [Medical_term]
Inflammation of a vein.
phlebotomy [Medical_term]
Withdrawal of blood from a vein.
phlegm [Medical_term]
Mucus, especially mucus produced by the lungs during inflammation or infection.
phobia [Medical_term]
Any persistent, unreasonable abnormal fear.
phonation [Medical_term]
Making vocal sounds.
photophobia [Medical_term]
Abnormal intolerance of light.
physician [Medical_term]
A doctor. An authorized practitioner of medicine.
physiology [Medical_term]
The branch of medicine that deals with the function of the various parts of the living organism.
pigeon toe [Medical_term]
A foot condition where the toes turn in.
piles [Medical_term]
An enlarged vein inside or just outside the rectum.
pilus [Medical_term]
Hair.
pimple [Medical_term]
A small, elevated skin lesion
pinguecula [Medical_term]
A yellowish spot on the cornea of the eye that sometimes occurs in the elderly.
pink eye [Medical_term]
Inflammation of the conjunctiva. Also called conjunctivitis.
pinna [Medical_term]
The part of the ear that’s projected outside of the head.
pinworm [Medical_term]
A parasite, Enterobius vermicularis, that can cause intense itching around the anus.
pituitary gland [Medical_term]
The gland that secretes hormones that influence body growth, metabolism and the function of other endocrine glands.
pityriasis [Medical_term]
A skin condition in which the skin forms thin, dry scales.
placebo [Medical_term]
A harmless substance that resembles a medicine; often used to test the effectiveness of medicines.
placenta [Medical_term]
A spongy structure that grows on the uterine wall during pregnancy and provides nutrition to the fetus.
plague [Medical_term]
1. Any contagious epidemic disease that is deadly. 2. An infectious disease caused by Yersinia pestis that can be spread from animals to humans and is normally spread to humans by fleas (called bubonic plague) or from person to person by respiratory droplets (called pnenmonic plague). Both forms have a high death rate.
plantar [Medical_term]
Having to do with the sole of the foot.
plasma [Medical_term]
The fluid portion of the blood.
platelet [Medical_term]
A thrombocyte, the smallest of the formed components of blood, associated with blood clotting.
pleura [Medical_term]
The membrane surrounding the lungs and lining the walls of the chest cavity.
pleurisy [Medical_term]
Inflammation of the pleura.
plexus [Medical_term]
A network of nerves or veins.
plumbism [Medical_term]
Chronic lead poisoning.
pneumoconiosis [Medical_term]
Any of several lung diseases caused by inhaling particles of industrial substances.
pneumonia [Medical_term]
Acute inflammation or infection of the lungs.
pneumothorax [Medical_term]
The buildup of air or gas in the chest cavity. May cause lung collapse.
podiatry [Medical_term]
The branch of medicine that pertains to the foot and its ailments.
poison [Medical_term]
A substance that causes illness or death when eaten, drunk or absorbed into the body.
poliomyelitis [Medical_term]
An acute, infectious disease that attacks the central nervous system. Sometimes causes paralysis that can result in permanent deformities. Vaccines are available. Also called polio.
pollen [Medical_term]
The male fertilizing element of flowering plants.
polycythemia [Medical_term]
Abnormal increase in the number of red blood cells or hematocrit.
polydactyly [Medical_term]
Extra fingers or toes.
polydipsia [Medical_term]
Excessive thirst.
polyhidrosis [Medical_term]
Excessive sweating.
polyp [Medical_term]
A growth extending outward from a mucous membrane.
polypectomy [Medical_term]
Surgical removal of a polyp.
polyuria [Medical_term]
Excessive, frequent urination.
pons [Medical_term]
A piece of connecting tissue, specifically the bridge of white matter at the base of the brain.
popliteal [Medical_term]
Having to do with the area behind the knee.
pore [Medical_term]
A small opening.
posterior [Medical_term]
At or toward the back.
postoperative [Medical_term]
After surgery.
postpartum [Medical_term]
After childbirth.
preeclampsia [Medical_term]
A complication of pregnancy. The development of hypertension with protein in the urine, buildup of fluid (edema) or both.
premenstrual syndrome [Medical_term]
PMS. Headache, irritability, edema (swelling), abdominal discomfort, pelvic pain and nausea in the days before the start of the menstrual periods of some women.
prepuce [Medical_term]
A covering fold of skin, such as the foreskin of the penis.
presbyopia [Medical_term]
A form of farsightedness occurring after middle age. Caused by a loss of elasticity of the crystalline lens with age.
prescription [Medical_term]
A physician’s written direction for preparation and use of a medicine.
prevalence [Medical_term]
The number of cases of a specific disease in a given population at a certain point in time.
proctitis [Medical_term]
Inflammation of the rectum.
prodrome [Medical_term]
Symptoms marking the onset of an illness.
progeny [Medical_term]
Children.
progeria [Medical_term]
Premature aging.
progesterone [Medical_term]
A steroid produced by the ovaries to prepare the uterus for the reception and development of the fertilized ovum (egg).
prognosis [Medical_term]
The probable outcome of a disease.
prolactin [Medical_term]
The pituitary hormone that promotes the growth of breast tissue and encourages the production of milk.
prolapse [Medical_term]
The falling or slipping out of place of an internal organ, such as when the uterus falls into the vagina.
prostate [Medical_term]
A male reproductive gland that surrounds the neck of the bladder and the urethra.
prosthesis [Medical_term]
An artificial substitute for a missing body part.
protein [Medical_term]
An organic compound composed primarily of amino acids.
proteinuria [Medical_term]
Protein in the urine.
pruritus [Medical_term]
Itching.
psoriasis [Medical_term]
Chronic, recurring skin disease characterized by red, inflamed patches covered with scales.
psychiatry [Medical_term]
The branch of medicine that deals with the diagnosis, treatment and prevention of mental disorders.
psychoanalysis [Medical_term]
A technique developed by Sigmund Freud for the diagnosis and treatment of mental disorders.
psychology [Medical_term]
The scientific study of mental processes and behavior.
psychopath [Medical_term]
A person with a mental disorder characterized by the conspicuous disregard for the rights and needs of others, the lack of remorse and the lack of empathy for others.
psychosis [Medical_term]
A mental disorder with serious derangement of the thinking process, often including delusions or hallucinations.
ptilosis [Medical_term]
Shedding of the eyelashes.
ptosis [Medical_term]
A prolapse or falling of some organ or structure, especially the drooping of a paralyzed upper eyelid.
puberty [Medical_term]
The stage of life during which the secondary sexual characteristics begin to develop and sexual reproduction becomes possible.
pubis [Medical_term]
The most forward bone of the pelvis.
puerperium [Medical_term]
The period of time just after childbirth.
pulmonary [Medical_term]
Having to do with the lungs.
pulse [Medical_term]
The heartbeat as felt through the walls of an artery.
puncture [Medical_term]
A wound produced by a pointed object.
pupil [Medical_term]
The opening in the center of the iris.
purpura [Medical_term]
Movement of blood into the soft tissues, producing bruises.
purulent [Medical_term]
Containing pus.
pus [Medical_term]
A thick fluid produced in certain infections.
pustule [Medical_term]
A small pus-containing blister.
pyelitis [Medical_term]
Inflammation of the urine-collecting system within the kidney.
pyelonephritis [Medical_term]
Kidney infection.
pylorus [Medical_term]
The junction of the stomach and the small intestine.
pyodermatitis [Medical_term]
Skin infection producing pus.
pyridoxine [Medical_term]
Vitamin B6, sometimes used to treat nausea in pregnancy or to manage premenstrual syndrome symptoms.
pyrogen [Medical_term]
Something that causes fever.

Q

quackery [Medical_term]
Misrepresentation of a product’s or person’s ability to diagnose and treat disease.
quadriceps [Medical_term]
The name applied collectively to a group of four thigh muscles that insert together into the tendon surrounding the kneecap.
quadriplegia [Medical_term]
Loss of feeling and movement of the arms and legs.
quarantine [Medical_term]
Any isolation or restriction placed on movement to or from a place where communicable diseases have been diagnosed.
quickening [Medical_term]
The first perceived movements of a fetus in the uterus.

R

rabies [Medical_term]
A fatal, if untreated, viral disease of mammals that’s spread to humans by the bite of infected animal.
rad [Medical_term]
Radiation absorbed dose. A unit of measurement of the absorbed dose of ionizing radiation.
radiculopathy [Medical_term]
A disease or other problem affecting a nerve root.
radioisotope [Medical_term]
A radioactive form of an element. Used in certain diagnostic tests.
radiology [Medical_term]
The branch of medicine that deals with the use of x-rays.
radon [Medical_term]
A colorless, radioactive gas produced by the decay of radium. The presence of sufficient quantities of this gas in homes is linked with the development of lung cancer.
rash [Medical_term]
Visual marks or spots that appear on the skin.
Raynaud’s phenomenon [Medical_term]
A circulation disorder characterized by changes of blood flow, resulting in the hands and feet becoming pale, followed by redness and pain. This condition may be caused by cold, vibrations or emotions.
recrudescence [Medical_term]
To reoccur after a temporary absence.
rectum [Medical_term]
The last portion of the large intestine.
reflux [Medical_term]
A return flow.
refraction [Medical_term]
1. The bending of a ray or wave of light from one medium to a medium of a different density. 2. The amount of error in the eye and the correction of that error with glasses to restore normal vision.
regurgitation [Medical_term]
The return of partly digested food from the stomach to the mouth or of blood in a reverse direction through the valves of the heart.
rehabilitation [Medical_term]
The process of restoring one’s ability to live as normally as possible after an injury or illness.
Reiter’s syndrome [Medical_term]
A complex group of symptoms marked by inflammation of the urethra or cervix, conjunctiva and joints.
relapse [Medical_term]
The return of a disease after its apparent resolution.
REM [Medical_term]
Rapid eye movement. The phase of sleep associated with dreaming and distinguished from the other stages of sleep by rapid movement of the eyes.
remedy [Medical_term]
Anything that cures.
remission [Medical_term]
Improvement of the symptoms of a disease.
renal [Medical_term]
Having to do with the kidney.
reservoir [Medical_term]
A medical term used to describe a source of organisms causing a disease.
respiration [Medical_term]
The act or process of breathing. The process by which a living organism or cell takes in oxygen from the air or water and uses it.
resuscitation [Medical_term]
Restoring the heartbeat and/or breathing in someone who’s apparently dead. Also called artificial respiration.
retardation [Medical_term]
Delay or halt of any process such as mental or physical development.
retina [Medical_term]
The innermost layer of the eyeball. The retina contains the light-sensing rods and cones used for vision.
retinopathy [Medical_term]
Degeneration of the retina.
retrobulbar [Medical_term]
Behind the eyeball.
retrovirus [Medical_term]
A virus that produces DNA from RNA (the opposite of the normal order). A group of viruses that includes HIV.
Rh factor [Medical_term]
One of the antigens present on red blood cells. Used in categorizing the type of blood a person has.
rheumatism [Medical_term]
Pain in the muscles and joints. Characterized by inflammation and stiffness. Sometimes used to describe arthritis, bursitis and sciatica.
rhinitis [Medical_term]
Inflammation of the mucous membranes of the nose.
rhinoplasty [Medical_term]
Plastic surgery of the nose.
rhinorrhea [Medical_term]
Runny nose.
rickets [Medical_term]
A condition resulting from a vitamin D deficiency in childhood. Characterized by the softening of the bones and associated deformities.
ringworm [Medical_term]
A fungal infection of the skin.
Rocky Mountain spotted fever [Medical_term]
An infectious disease spread by tick bites.
roseola infantum [Medical_term]
A common viral infection of young children. Characterized by high fever, irritability and a faint rose-colored rash that appears on the fourth day when the fever subsides.
rubella [Medical_term]
A mild childhood disease that causes fever and rash. Although rubella is mild in childhood, it’s dangerous to pregnant women because it can cause birth defects. Also called German measles.
rubeola [Medical_term]
A type of measles that can lead to serious complications and death.

S

sac [Medical_term]
Pouch; a bag-like structure.
saccharin [Medical_term]
A compound that’s hundreds of times sweeter than table sugar. Used as an artificial sweetener.
sacroiliac [Medical_term]
Having to do with the joint formed by the sacrum and the ilium in the lower back.
saliva [Medical_term]
An enzyme-containing thin, watery secretion of the salivary glands.
salivary gland [Medical_term]
Any one of the three pairs of glands of the mouth (parotid, submaxillary and sublingual) that release saliva.
salmonella [Medical_term]
A form of food poisoning characterized by fever and intestinal disorder due to Salmonella bacteria.
salve [Medical_term]
Ointment.
sanguineous [Medical_term]
Bloody.
scabies [Medical_term]
An itchy, contagious skin condition caused by mites.
scapula [Medical_term]
The shoulder blade.
scarlet fever [Medical_term]
Fever and skin reaction caused by certain strains of streptococcus bacteria, usually following a streptococcal infection of the throat, middle ear or skin.
schizophrenia [Medical_term]
A chronic mental disorder characterized by an inability to differentiate reality from fantasy. Often associated with hallucinations or delusions.
sciatica [Medical_term]
Pain or inflammation going from the back to the buttock along the sciatic nerve.
sclera [Medical_term]
The tough white covering of the eyeball.
scleritis [Medical_term]
Inflammation of the sclera, causing pain, redness and possible loss of vision. Can be a complication of rheumatoid arthritis.
scleroderma [Medical_term]
A chronic disease characterized by hardening or thickening of the skin due to abnormal tissue growth.
sclerosis [Medical_term]
Hardening.
scotoma [Medical_term]
A blind spot in an area of otherwise normal vision.
scratch test [Medical_term]
A test for allergies in which small amounts of potential allergens are inserted in small scratches made in the skin.
scrotum [Medical_term]
The skin-covered sac that contains the testes.
scurvy [Medical_term]
A condition caused by vitamin C deficiency. Symptoms include loss of appetite, bleeding gums, bruising, inability to gain weight and irritability.
sebaceous cyst [Medical_term]
A benign cyst containing oil and cells from a sebaceous gland.
sebaceous glands [Medical_term]
Small glands in the skin that release an oily substance through the hair follicles.
seborrhea [Medical_term]
Greasy scales or cheesy plugs resulting from overproduction of the sebaceous glands.
seborrheic keratoses [Medical_term]
Skin growths that may be smooth or warty-looking, of varying size, and flesh-colored, brown or black. Often appear on the trunk or temples. Often occur in middle-aged and elderly people. Also called senile warts.
seizure [Medical_term]
An attack of epilepsy.
semen [Medical_term]
The ejaculate of the male consisting of sperm and secretions from the prostate, seminal glands and other glands.
semicircular canals [Medical_term]
The three loop-shaped tubular passages of the inner ear that control the sense of balance.
seminiferous [Medical_term]
Carrying or producing semen.
sensorium [Medical_term]
The state of a person’s mental awareness.
sepsis [Medical_term]
When disease-causing bacteria from an area of infection spread into the bloodstream and tissues.
septum [Medical_term]
A wall dividing an organ or cavity, as in the nose.
serology [Medical_term]
The study of the antigen-antibody reaction.
serotonin [Medical_term]
A chemical used to transmit information from one nerve cell to another.
serum [Medical_term]
The clear, yellowish-colored liquid portion of blood.
shigellosis [Medical_term]
A diarrheal disease caused by Shigella bacteria.
shingles [Medical_term]
A viral infection of certain sensory nerves that causes pain and blisters on the skin along the course of the infected nerve. Also called herpes zoster.
shock [Medical_term]
A disorder resulting from disruption of the circulation of the blood that can upset all body functions.
shoulder [Medical_term]
The ball-and-socket joint connecting the arm with the body.
shunt [Medical_term]
To surgically divert the flow (such as of blood) from one organ or pathway to another.
Siamese twins [Medical_term]
Identical twins born joined together.
sickle cell anemia [Medical_term]
A genetic condition characterized by abnormal red blood cells containing a defective form of hemoglobin. Sickle cell anemia occurs in people who inherit the gene from both parents. Found chiefly in black populations and causes anemia, jaundice and recurring attacks of fever and pain in the arms, legs and abdomen.
sickle cell trait [Medical_term]
Inheriting the gene for sickle cell anemia from only one parent. It causes no symptoms.
sigmoid [Medical_term]
S-shaped.
sinew [Medical_term]
A tendon or fibrous cord.
sinus [Medical_term]
A cavity in a bone or other tissue. Commonly used to describe the cavities in the skull that open into the nasal cavity.
sinusitis [Medical_term]
Inflammation and infection of the sinuses.
sitz bath [Medical_term]
A bath in which only the hips and buttocks are immersed in water for relief of rectal or vaginal discomfort.
skeleton [Medical_term]
The hard bony framework of the human body that supports the tissues and protects the organs.
skull [Medical_term]
The bony framework of the head.
smallpox [Medical_term]
A viral disease that was once highly contagious. Characterized by high fever, vomiting, and blisters and sores on the skin. Vaccination has eliminated this disease.
smooth muscle [Medical_term]
A type of muscle tissue controlled by the involuntary nervous system, occurring in the walls of the uterus, intestines or blood vessels.
sneeze [Medical_term]
To exhale breath from the nose and mouth in a sudden, involuntary action as a result of irritation of the mucous membranes of the nose.
Snellen’s chart [Medical_term]
A chart of block letters used to test distant vision.
snoring [Medical_term]
Harsh breathing sounds during sleep caused by the vibration of the soft palate during inhalation.
soft palate [Medical_term]
The soft part of the roof of the mouth in the back, toward the throat.
soft tissue [Medical_term]
The substance of an organic body or organ consisting of cells and intercellular materials. The muscles and other nonbony tissues of the body.
solar plexus [Medical_term]
The network of nerves in the center of the abdomen.
spasm [Medical_term]
A sudden, involuntary contraction of a muscle or group of muscles.
specimen [Medical_term]
A sample taken to study the nature of the whole.
speculum [Medical_term]
An instrument for opening a body cavity to permit visual inspection.
sperm [Medical_term]
The male germ cell. Also called spermatozoon.
sphincter [Medical_term]
A ring-shaped muscle that surrounds a natural opening in the body and can open or close it by relaxing or contracting.
sphygmomanometer [Medical_term]
An instrument for measuring blood pressure. An inflatable blood-pressure cuff.
spina bifida [Medical_term]
A birth defect caused by imperfect closure of part of the spinal column, exposing some of the nervous system.
spirochete [Medical_term]
Spiral-shaped bacteria.
spleen [Medical_term]
The blood-forming and -storing organ located under the ribs in the upper left portion of the abdomen.
splenomegaly [Medical_term]
Enlargement of the spleen.
splint [Medical_term]
A device for holding broken or injured parts in place.
spondylitis [Medical_term]
Inflammation of the vertebrae.
spondylosis [Medical_term]
Narrowing of the spinal column resulting in reduction of the spaces between the vertebrae which may cause compression of the nerve roots.
sprain [Medical_term]
A twisting or stretching injury of a ligament or muscle of a joint, with or without dislocating a bone.
spur [Medical_term]
A projecting body. For example, from a bone.
sputum [Medical_term]
Mucus secreted by the lungs, bronchi and trachea that’s ejected by coughing or clearing the throat.
stapedectomy [Medical_term]
Surgical removal of the stapes.
stapedioplasty [Medical_term]
Replacement of the stapes with other materials (wire, bone, plastic).
stapes [Medical_term]
A small bone of the middle ear. Also called the stirrup.
stenosis [Medical_term]
Narrowing of a body passage or opening.
sterile [Medical_term]
1. Free from living microorganisms. 2. Unable to have children.
sternum [Medical_term]
The breastbone.
Stevens-Johnson reaction [Medical_term]
An inflammatory disease characterized by rapid attack of fever, skin blisters and sores on the lips, eyes, mouth, nasal passage and genitals.
stoma [Medical_term]
1. Mouth-like opening. 2. An opening used for drainage.
stomatitis [Medical_term]
Inflammation of the mucosa of the mouth.
stool [Medical_term]
Feces, or bowel movement.
strabismus [Medical_term]
A deviation in which both eyes aren’t trained on the same spot. Also called crossed eyes or lazy eye.
strain [Medical_term]
1. To filter. 2. Excessive effort. 3. Overstretching a portion of a muscle. 4. Within a species, a group of organisms characterized by a particular trait or quality.
stress [Medical_term]
1. Pressure; strain. 2. Any condition that causes mental or physical strain or tension.
stridor [Medical_term]
A harsh or squeaky sound in breathing, often associated with a blocked larynx.
stroke [Medical_term]
Deprivation of the blood supply to the brain due to blockage of a blood vessel. Results in unconsciousness, paralysis or other neurologic symptoms.
stye [Medical_term]
Infection of one of the sebaceous glands of the edge of the eyelid.
subcutaneous [Medical_term]
Just beneath the skin.
subdural [Medical_term]
Beneath the dura mater, the covering of the brain.
subliminal [Medical_term]
Below the threshold of conscious awareness.
subluxation [Medical_term]
Partial dislocation.
subungual [Medical_term]
Beneath a nail.
sucrose [Medical_term]
A natural sugar obtained from sugar cane and sugar beets used as a sweetening agent. Also called table sugar.
suicide [Medical_term]
Taking one’s own life.
sunburn [Medical_term]
A skin inflammation caused by prolonged exposure to ultraviolet radiation from the sun, tanning beds or other sources.
sunstroke [Medical_term]
A serious failure of the body’s heat-regulating mechanism resulting from excessive exposure to intense heat. Also called heat stroke.
superinfection [Medical_term]
Sudden growth of a different type of bacteria than the type originally diagnosed and treated. This is a common cause of treatment failure because the new type of bacteria is often resistant to first-line antibiotics.
suppository [Medical_term]
A cone-shaped solid mass of medication designed to be placed in the rectum or vagina.
surfactant [Medical_term]
A substance produced in the lungs that reduces surface tension and helps keep the small air sacs open.
surrogate [Medical_term]
A substitute.
suture [Medical_term]
1. The joining together of certain vertebrate bones, especially of the skull. 2. A stitch or stitches made to close a wound. 3. The material used in closing a wound with stitches.
synapse [Medical_term]
The tiny space between two nerve cells that allows the transmission of a nerve impulse.
syncope [Medical_term]
Fainting.
synergism [Medical_term]
The working together of different organs or parts of the body so that their combined action is greater than their individual effects.
synovia [Medical_term]
The clear lubricating fluid produced in joints, bursae and tendon sheaths.
syphilis [Medical_term]
A sexually transmitted disease caused by the spirochete Treponema pallidum.
systole [Medical_term]
The cardiac contraction of a heartbeat.
systolic [Medical_term]
Systolic blood pressure is the pressure when your heart is contracting, squeezing blood out.

T

tachycardia [Medical_term]
An abnormally rapid heartbeat.
tachypnea [Medical_term]
Rapid breathing.
talus [Medical_term]
A bone of the ankle.
Tanner staging [Medical_term]
A growth chart used to assess the stage of puberty based on pubic hair growth, the development of genitalia in boys and breasts in girls.
telogen effluvium [Medical_term]
Thinning hair. Rarely results in actual baldness.
temporomandibular joint [Medical_term]
TMJ. The joint between the lower jaw and the side of the head, located just in front of the ear.
tendinitis [Medical_term]
Inflammation of a tendon.
tendon [Medical_term]
A cord of strong white fibrous tissue connecting muscle to bone.
teratogen [Medical_term]
An agent that causes physical defects in a developing embryo.
testis [Medical_term]
The male gonad or reproductive organ.
testosterone [Medical_term]
One of the male sex hormones.
tetanus [Medical_term]
An infectious disease, often fatal, caused by a Clostridium tetani bacteria. The bacteria usually enters the body through wounds. Characterized by muscle spasms and convulsions. Also called lockjaw.
tetany [Medical_term]
A continuous muscle spasm.
thalassemia [Medical_term]
An inherited type of chronic anemia.
therapeutic [Medical_term]
A substance or treatment that’s effective in treating disease.
thoracentesis [Medical_term]
A surgical puncture and drainage of the chest cavity.
thoracic [Medical_term]
Having to do with the chest.
thorax [Medical_term]
The chest.
thrombocyte [Medical_term]
A platelet.
thromboembolism [Medical_term]
Blockage of a blood vessel by the piece of a blood clot that has broken loose from its original site.
thrombosis [Medical_term]
Formation of a blood clot within a blood vessel or the heart.
thrush [Medical_term]
Infection of the mouth by yeast. Characterized by milky-white lesions on the mouth, lips and throat.
thymus [Medical_term]
A ductless gland located behind the upper portion of the breastbone.
thyroid gland [Medical_term]
A large endocrine gland located in the front and sides of the neck and below the Adam’s apple. Essential for the regulation of growth and metabolism.
thyroxine [Medical_term]
The hormone from the thyroid gland that’s essential in metabolism.
tibia [Medical_term]
The larger of two bones in the lower leg.
tic [Medical_term]
An involuntary spasm or twitching of a muscle.
tinea [Medical_term]
A general term for fungal infections of the skin, usually combined with a description of the site or cause. Examples include tinea cruris or “jock itch,” and tinea pedis or “athlete’s foot.”
tinnitus [Medical_term]
Ringing in the ears. Sensation of a high-pitched sound that’s not actually present.
tissue [Medical_term]
A group of similar cells that together perform certain specialized functions.
tongue [Medical_term]
The muscular organ attached to the floor of the mouth. Used to speak, chew, swallow and taste.
tonsillectomy [Medical_term]
A procedure to remove the tonsils.
tonsils [Medical_term]
A pair of oval masses of lymphoid tissue, one on each side of the throat at the back of the mouth.
toxemia [Medical_term]
The presence of toxic substances in the blood from bacteria or body cells.
toxic [Medical_term]
Poisonous.
trachea [Medical_term]
The air passage extending from the throat to the bronchi. Also called the windpipe.
tracheostomy [Medical_term]
A surgical incision in the trachea (the windpipe) through which a rigid tube is inserted to allow air to enter.
trachoma [Medical_term]
A chronic infectious eye disease caused by Chlamydia infection of the eye. A leading cause of blindness worldwide.
transfusion [Medical_term]
Introduction of blood or blood products through a vein into the body’s circulation.
transplantation [Medical_term]
The transfer of living organs or tissue from a donor to another person or from one area in the body to another.
trauma [Medical_term]
Injury produced by an external force.
trench mouth [Medical_term]
An acute, severe bacterial infection of the gums and lining of the mouth.
triage [Medical_term]
A system of assigning priorities of medical treatment based on urgency, severity of injury and chance for survival.
triceps [Medical_term]
A muscle of the arm used to extend the forearm.
trichinosis [Medical_term]
Infection with a roundworm caused by consumption of larvae in undercooked pork or other infected meat.
trichomoniasis [Medical_term]
Infection with Trichomonas protozoa. Frequently causes vaginal itching and discharge in women. It’s usually acquired by sexual contact with an infected partner.
tricuspid valve [Medical_term]
The heart valve between the right atrium and the right ventricle.
trisomy [Medical_term]
The presence of an extra chromosome in addition to the usual pair. Down syndrome is an example of a condition caused by trisomy.
truss [Medical_term]
A device to keep a hernia in its proper place.
TSH [Medical_term]
Thyroid-stimulating hormone. A pituitary hormone that stimulates thyroid hormone production.
tuberculin [Medical_term]
A protein injected into the skin to test for tuberculosis infection.
tuberculosis [Medical_term]
An infectious disease caused by bacteria and characterized by the formation of tubercles in various tissues of the body, especially of the lungs.
tumor [Medical_term]
Overgrowth of tissue.
tussis [Medical_term]
Cough.
tympanic membrane [Medical_term]
The eardrum.
typhoid fever [Medical_term]
A bacterial infection with Salmonella typhi transmitted by contaminated water, milk or other foods. Proper sanitation and hygiene prevent the spread of disease.
typhus [Medical_term]
An infectious disease spread to people by the bite of ticks, mites, fleas and lice. Typhus is characterized by high fever, headache and a rash.

U

ulcer [Medical_term]
A localized sore in the skin or mucosal surfaces.
ulcerative colitis [Medical_term]
A chronic inflammatory disease of the large intestine characterized by bloody diarrhea.
ulna [Medical_term]
The larger of the two bones of the forearm.
umbilical cord [Medical_term]
A tough, cord-like structure connecting the fetus to the placenta for nourishment.
umbilicus [Medical_term]
The scar at the site of attachment of the umbilical cord. The navel or belly button.
ungual [Medical_term]
Having to do with the nails.
uremia [Medical_term]
The buildup in the blood of substances normally eliminated in the urine.
ureter [Medical_term]
A narrow tube that transfers urine from the kidney to the bladder.
urethra [Medical_term]
The tube that allows the bladder to empty outside the body.
urethral stricture [Medical_term]
A narrow area of the urethra that blocks the flow of urine.
urethritis [Medical_term]
Inflammation or infection of the urethra.
urinary bladder [Medical_term]
The organ that serves as a temporary storage place for urine. Also called the bladder.
urine [Medical_term]
The fluid composed of water and waste products that’s secreted by the kidneys.
urogenital [Medical_term]
Having to do with the urinary system and genitals.
urology [Medical_term]
The branch of medicine that deals with the urinary system in women and the urogenital system in men.
uterus [Medical_term]
A hollow muscular organ in women where the ovum (egg) is deposited and the embryo and fetus are developed.
uvula [Medical_term]
The fleshy mass hanging down from the soft palate above the back of the tongue.

V

vaccination [Medical_term]
Inoculation with weakened or dead microorganisms to develop immunity and prevent disease caused by the regular strain of that microorganism.
vaccine [Medical_term]
A preparation of killed or weakened microorganisms, given to treat or prevent disease.
vagina [Medical_term]
The muscular canal in women between the vulva and the uterus. It serves as the entry for spermatozoa and as the birth canal.
vaginismus [Medical_term]
Painful spasm of the vagina.
varicocele [Medical_term]
Dilated veins in the spermatic cord above or around the testis that can cause decreased sperm production on the affected side.
varicose veins [Medical_term]
Swollen, distended veins especially visible in the legs.
vas deferens [Medical_term]
The duct through which sperm travels from the testicle to the urethra of the penis.
vascular [Medical_term]
Of or having vessels, particularly the blood vessels.
vasculitis [Medical_term]
Inflammation of the walls of the small blood vessels.
vasectomy [Medical_term]
Surgical removal or tying of the vas deferens to prevent the passing of sperm. Used as a form of birth control.
vasoconstriction [Medical_term]
Causing the narrowing or closing (constriction) of blood vessels.
vasodilation [Medical_term]
Causing the widening or opening (dilation) of blood vessels.
vector [Medical_term]
An animal that spreads an infectious agent from one host to another. Also called a carrier.
vein [Medical_term]
A vessel that carries blood from the various parts of the body to the heart.
venom [Medical_term]
A toxin secreted by an animal.
venous [Medical_term]
Having to do with a vein.
ventricle [Medical_term]
1. Either of the two chambers that contract to pump blood from the heart. 2. Any of several small fluid-filled cavities in the brain.
verruca [Medical_term]
A small, hard, abnormal growth of the skin or mucous membranes caused by a virus.
vertebrae [Medical_term]
The bones that make up the spine.
vertigo [Medical_term]
A spinning sensation often accompanied by mild to severe nausea.
vesicle [Medical_term]
1. A small, sac-like cavity. 2. A blister.
vesicourethral reflux [Medical_term]
An abnormal condition that allows urine to flow from the bladder back into a ureter.
virus [Medical_term]
The agent of an infectious disease, smaller than bacteria, that must have a living host in order to grow or reproduce.
viscera [Medical_term]
The large internal organs.
vision [Medical_term]
The sense of sight.
vitamin [Medical_term]
An organic substance found in food and essential in small quantities for good health.
vitiligo [Medical_term]
A skin condition characterized by sharply defined white patches that contain no skin color (pigment).
vitreous humor [Medical_term]
The jelly-like material that fills the eyeball between the lens and retina.
vomiting [Medical_term]
Ejecting the contents of the stomach through the mouth.
vulva [Medical_term]
The external parts of the female reproductive tract surrounding the opening to the vagina.

W

wart [Medical_term]
A small, hard, abnormal growth of the skin or mucous membranes caused by a virus.
wheal [Medical_term]
A pimple or small itchy elevation of the skin caused by an allergen.
wheeze [Medical_term]
A whistling or squeaky breathing sound caused by the narrowing (constriction) or blocking of the airway.
whiplash [Medical_term]
An injury of the neck or spine due to a sudden, severe bending of the neck.
whooping cough [Medical_term]
A serious infectious respiratory disease of children. Named for the distinctive whooping sound made by the patient after a coughing spasm. Also called pertussis.
Wilms’ tumor [Medical_term]
A rapidly growing tumor of the kidney found in children.
Wilson’s disease [Medical_term]
A rare, inherited disorder that occurs when copper pools in the red blood cells. May cause tremors, muscle rigidity, speech problems and dementia.
withdrawal [Medical_term]
The act or process of giving up the use of a drug to which one has become addicted or dependent.
wrist [Medical_term]
The joint or part of the arm between the hand and the forearm.

X

xanthelasma [Medical_term]
Fatty deposits that appear as yellowish patches, or plaques, under the skin, often appearing in or near the eyelids.
xanthoma [Medical_term]
A tumor-like deposit of fatty substances in the skin.
xenograft [Medical_term]
Transplantation of tissue or organs from an individual of one species to another unrelated species, such as a pig’s heart valve implanted in a human.
xeroderma [Medical_term]
Dryness of the skin.

Y

yeast [Medical_term]
A single-celled fungus that reproduces by budding and may lead to infections of the skin or other moist areas.
yellow fever [Medical_term]
An acute viral illness spread by mosquito bites. Characterized by fever and jaundice.

Z

zoonosis [Medical_term]
A disease that can be spread to people by animals.
zoster [Medical_term]
A viral infection of certain sensory nerves that causes pain and an eruption of blisters on the skin along the course of the infected nerve.
zygote [Medical_term]
A fertilized ovum (egg).

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