Dictionary

Enter a word or phrase below to search our online dictionary of over 1,300 general medical terms, or click on a letter of the alphabet to view all terms beginning with that letter:

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Search for 'C'

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