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:
Search for 'B'
| Phrase | Definition |
|---|---|
| bacteremia | The presence of bacteria in the blood. |
| bacteria | 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 | The presence of bacteria in the urine. |
| Baker's cyst | A swelling of the knee caused by an escape of fluid from a sac behind the knee. |
| ballism | Quick, jerking movements that occur in people with chorea. |
| barium | A chalky substance used in x-ray studies of the digestive tract to highlight abnormalities. |
| barotrauma | 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 | A cyst caused by an infection of the glands on the vaginal wall. |
| BCG (bacille Calmette-Guerin) vaccine | 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 | An ulcer caused by chafing or by the pressure of the body against the bed. |
| Bell's palsy | 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 | 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 | A nonlife-threatening condition. Not malignant. Not cancerous. |
| benign familial tremor | 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 | A deficiency disease caused by dietary insufficiency of vitamin B1 (thiamine). Symptoms include general weakness and painful rigidity. |
| biceps | 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 | A tooth named for the two-pointed projections on the crown. |
| bifocals | 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 | A clear yellow fluid produced by the liver and stored in the gallbladder. Aids in digestion. |
| bilirubin | 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 | Using both eyes at the same time. Binocular vision is the most important element of depth perception. |
| biopsy | Removal and exam of a tissue sample taken from a living body. This procedure helps determine if the tissue is cancerous. |
| bipolar affective disorder | 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 | 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 | 1. Short-term loss of vision and consciousness. 2. In an alcoholic person, loss of memory for a period of time. |
| bladder | The organ that temporarily stores a substance. Commonly used in reference to the urinary bladder, which holds urine until it's eliminated. |
| blepharitis | Inflammation of the eyelid. |
| blepharoplasty | Plastic surgery on the eyelid. |
| blindness | Loss of vision. Legally, visual acuity less than 20/200 with glasses. |
| blister | Buildup of watery or bloody fluid under the skin. |
| blood | 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 | Infection within the circulatory system. A potentially life-threatening condition that requires prompt treatment. |
| blood pressure | The pressure exerted by the blood against the walls of the blood vessels. |
| boil | A skin infection characterized by a localized buildup of pus. |
| bone marrow | The tissue within the cavity of the bones where new blood cells are made. |
| Borrelia | A class of disease-causing bacteria that includes the organisms that cause relapsing fever and Lyme disease. |
| botulism | An extremely dangerous form of food poisoning caused by the toxin of Clostridium botulinum. |
| bovine | Having to do with cattle. For example, bovine insulin is insulin obtained from cattle. |
| bowel | See intestine. |
| Bowen's disease | A precancerous skin condition that first appears as psoriasis-like scaling. |
| bowleg | A deformity of the legs in which the space between the knees is greater than normal. |
| brace | A device used to support a body part, correct or prevent deformities, or control movement. |
| bradycardia | Slow heart rate and pulse, usually slower than 60 beats per minute. |
| Braxton Hicks contractions | Contractions of the uterus during pregnancy that are sometimes mistaken for labor. Also called false labor. |
| breasts | Milk-secreting glands protruding from the upper front part of a woman's body. |
| breech birth | A birth in which the feet or buttocks of the baby appear first through the birth canal. |
| bridge | 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 | Nephritis. A group of kidney diseases manifested by albumin in the urine and edema (swelling). |
| bronchi | The tubular passages, also called bronchial tubes, that carry air into the lungs. |
| bronchiolitis | An infection of the bronchioles, the tiny air tubes in the lungs. |
| bronchitis | Inflammation of the bronchi. |
| bronchospasm | Contraction of the muscle in the walls of the bronchi. |
| bronze diabetes | 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 | An infection characterized by fluctuating fever, headache, anemia and vague physical discomfort that's transmitted to humans from domesticated goats, pigs and cattle. |
| bruise | Discoloration of the skin due to a buildup of blood in the underlying soft tissues. Also called a contusion. |
| bruxism | Grinding of the teeth. |
| bubo | 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 | 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 | An eating disorder characterized by binge eating followed by vomiting or use of laxatives. Usually caused by a variety of psychological reasons. |
| bunion | Localized swelling of the big toe at its joint with the foot. |
| bursa | A small, fluid-filled sac that allows one part of a joint to move freely over another part. |
| bursitis | Inflammation of a bursa. |
