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Bacteremia - the presence of bacteria in the bloodstream.
Balance - biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position; normal balance depends on information from the labyrinth in the inner ear, and from other senses such as sight and touch, as well as from muscle movement.
Balance disorder - disruption in the labyrinth, the inner ear organ that controls the balance system allowing individuals to know where their bodies are in the environment.
Balloon urethroplasty - a procedure in which a thin tube with a balloon is inserted into the opening of the penis and guided to the narrowed portion of the urethra (the tube that carries urine from the bladder to the outside of the body). The balloon is then inflated to widen the urethra and ease the flow of urine.
Barium - a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an X-ray.
Barium enema (also called lower GI, or gastrointestinal, series) - an X-ray procedure that examines the rectum, large intestine, and lower part of the small intestine. A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an X-ray) is given into the rectum as an enema.
Barium beefsteak meal - an X-ray exam used to assess how well the stomach is working and to detect emptying problems that may not show up on another test. During this test, the patient eats a meal containing barium, allowing the radiologist to watch the stomach as it digests the meal.
Barium swallow (also called upper gastrointestinal series or upper GI series) - an X-ray exam used to assess the upper part of the GI system (esophagus, stomach, and small intestine). A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an X-ray) is swallowed, and the progress of the barium through the esophagus, stomach, and small intestine is documented with X-rays.
Barotrauma - injury to enclosed parts of the body, such as the ear or lung, due to rapid or extreme changes in air pressure.
Basal body temperature - temperature of a person's body taken first thing in the morning after several hours of sleep and before any activity, including getting out of bed or talking; often charted to determine the time of ovulation.
Basal cell carcinoma - the most common form of skin cancer; characterized by small, shiny, raised bumps on the skin that may bleed.
Basal cells - a type of cells found in the outer layer of skin. Basal cells are responsible for producing the squamous cells in the skin.
Basal ganglia - several large clusters of nerve cells, including the striatum and the substantia nigra, deep in the brain below the cerebral hemispheres.
Basal metabolic rate (BMR) - a measurement of energy required to keep the body functioning at rest. Measured in calories, metabolic rates increase with exertion, stress, fear, and illness.
Base - bottom portion of lower lobes of the lungs, located just above the diaphragm.
Bed sores (also called pressure sores, pressure ulcers, or decubitus ulcers) - ulcers that occur on areas of the skin that are under pressure from lying in bed, sitting in - ulcers that occur on areas of the skin that are under pressure from lying in bed, sitting in wheelchairs, wearing a cast, or being immobile for a long period of time.
Belching (Also called burping.) - noisy release of gas from the stomach through the mouth.
Bell's palsy - a condition in which the nerve that controls the face muscles becomes inflamed, causing weakness or paralysis of the muscles on one side of the face. It usually resolves without treatment within a few weeks to months.
Benign - non-cancerous.
Benign paroxysmal positional vertigo (BPPV) - balance disorder that results in a sudden onset of dizziness, spinning, or vertigo that occurs when suddenly moving the head from one position to another or changing the body's position.
Benign prostatic hyperplasia (also called BPH or benign prostatic hypertrophy) - an enlargement of the prostate caused by disease or inflammation. It is not cancer, but its symptoms are often similar to those of prostate cancer.
Benign tumor - an abnormal growth that is not cancer and does not spread to other areas of the body.
Bereavement - to be in a sad or lonely state due to a loss or death.
Bernstein test - a test done to find out if heartburn is caused by acid in the esophagus; involves dripping a mild acid, similar to stomach acid, through a tube placed in the esophagus.
Beta blocker - an antihypertensive medication that limits the activity of epinephrine (a hormone that increases blood pressure).
Beta cells - cells that make insulin; found in areas of the pancreas called the islets of Langerhans.
Beta thalassemia - an inherited blood disorder affecting the beta chains of the hemoglobin molecule.
Bezoar - ball of food, mucus, vegetable fiber, hair, or other material that cannot be digested in the stomach, which can cause blockage, ulcers, and bleeding.
Biarthrodial muscles - muscles that span over two joints and have a function over those joints.
Bilateral - affecting both sides of the body. For example, bilateral breast cancer is cancer occurring in both breasts at the same time.
Bile - yellowish-brown or green fluid secreted by the liver that carries away waste and aids in the digestive process.
Bile acids - acids made by the liver that work with bile to break down fats.
Bile ducts - tubes that carry bile from the liver to the gallbladder for storage, and to the small intestine for use in digestion.
Biliary atresia - condition present from birth in which the bile ducts inside or outside the liver do not have normal openings. Bile becomes trapped in the liver, causing jaundice and cirrhosis. Without surgery, the condition may cause death.
Biliary stricture - narrowing of the biliary tract from scar tissue. The scar tissue may result from injury, disease, pancreatitis, infection, or gallstones.
Biliary tract (also called biliary system or biliary tree) - the gallbladder and the bile ducts.
Bilirubin - a yellowish-green substance formed when hemoglobin breaks down. Bilirubin gives bile its color. Bilirubin is normally passed in stool. Too much bilirubin causes jaundice.
Binge eating disorder - an illness that resembles bulimia nervosa and is characterized by episodes of uncontrolled eating or bingeing. It differs from bulimia, however, because its sufferers do not purge their bodies of the excess food, via vomiting, laxative abuse, or diuretic abuse.
Bingeing - a type of eating disorder in which a person engages in a destructive pattern of excessively overeating, called bingeing.
Binocular vision - the ability to use both eyes at once.
Biological therapy (also called immunotherapy, biotherapy, or biological response modifier therapy) - a type of treatment that uses the body's immune system, either directly or indirectly, to fight cancer or to lessen side effects that may be caused by some cancer treatments.
Biopsy - a procedure performed to remove tissue or cells from the body for examination under a microscope.
Birthmark - abnormality of the skin that is present at birth or shortly afterward.
Bismuth subsalicylate - nonprescription medication used to treat diarrhea, heartburn, indigestion, and nausea; also part of the treatment for ulcers caused by the bacterium Helicobacter pylori.
Bladder - a triangular-shaped, hollow organ located in the lower abdomen that holds urine. It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder's walls relax and expand to store urine, and contract and flatten to empty urine through the urethra.
Bladder instillation (also called a bladder wash or bath) - a procedure in which the bladder is filled with a solution that is held for varying periods of time, from a few seconds to 15 minutes, before being drained through a catheter.
Blasts - immature blood cells.
Blepharoplasty (also called eyelid lift) - a procedure in which the physician surgically removes excess fat, muscle, and skin from both the upper and lower eyelids to redefine the shape of the eye.
Blink rate - the number of times per minute that the eyelid automatically closes - normally 10 to 30 per minute.
Blister - a raised area on the skin containing fluid. The fluid can be blood or serum, the clear liquid portion of the blood.
Bloating - fullness or swelling in the abdomen that often occurs after meals.
Blood - the life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood circulates through the body's heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues.
Blood banking - the process that takes place in the laboratory to ensure that donated blood, or blood products, are safe before they are used in blood transfusions and other medical procedures. Blood banking includes typing the blood for transfusion and testing for infectious diseases.
Blood clot - a gelled mass of blood tissue.
Blood glucose - the main sugar that the body makes from food; cells cannot use glucose without the help of insulin.
Blood plasma - the fluid part of blood that contains nutrients, glucose, proteins, minerals, enzymes, and other substances.
Blood pressure - pressure of blood against the walls of a blood vessel or heart chamber.
Blood pressure cuff - a device usually placed around the upper of the arm to measure blood pressure.
Blood-brain barrier - the protective mechanism that protects the brain cells from certain substances that may be carried in the blood.
Body mass index (BMI) - the number, derived by using height and weight measurements, that gives a general indication if weight falls within a healthy range.
Boil - tender, swollen areas that form around hair follicles.
Bone - living tissue that makes up the body's skeleton.
Bone density - measurement of the bone's mass in relation to its volume.
Bone graft - a surgical procedure in which healthy bone is transplanted from another part of the patient's body into the affected area.
Bone marrow - the soft, spongy tissue found inside bones. It is the medium for development and storage of about 95 percent of the body's blood cells.
Bone marrow aspiration and biopsy - a procedure in which marrow is removed by aspiration or a needle biopsy under local anesthesia. In aspiration biopsy, a fluid specimen is removed from the bone marrow. In a needle biopsy, marrow cells (not fluid) are removed. These methods are often used together.
Bone marrow transplantation (BMT) - the transfusion of healthy bone marrow cells into a person after their own unhealthy bone marrow has been eliminated.
Bone scan - a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation.
Booster seat - a seat used to help raise a child in a vehicle so that the vehicle's seat belt fits properly.
Borborygmi - rumbling sounds, or stomach "growling," caused by gas moving through the intestines.
Borderline personality disorder - a condition in which people exhibit instability in their perceptions of themselves, and have difficulty maintaining stable relationships. Moods may also be inconsistent, but never neutral - their sense of reality is always seen in "black and white." People with borderline personality disorder often feel as though they lacked a certain level of nurturing while growing up and, as a result, incessantly seek a higher level of caretaking from others as adults. This may be achieved through manipulation of others, leaving them often feeling empty, angry, and abandoned, which may lead to desperate and impulsive behavior.
Botanical - relating to plants and plant life.
Botulinum toxin type A (also called Botox) - an injectable medication made from the bacteria that causes botulism, used to treat certain medical conditions and as a cosmetic treatment for wrinkles. An injection of botulinum toxin into specific muscles will immobilize those muscles, preventing them from forming wrinkles and furrows.
Bowel - another word for the small and large intestines.
Bowel movement - body wastes passed through the rectum and anus.
Bowel prep - process used to clean the colon with enemas and a special drink; used before surgery of the colon, colonoscopy, or barium X-ray.
brachytherapy - a type of radiation treatment in which the radioactive substance is placed inside the patient as close as possible to the area being treated.
"Brady-" - prefix meaning slow.
Bradycardia - abnormally slow heartbeat.
Bradykinesia - slowness of movement.
Bradyphrenia - slowness of thought processes.
Brain attack (also called stroke) - occurs when brain cells die because of inadequate blood flow to the brain.
Brain scan - an imaging method used to find abnormalities in the brain, including brain cancer and cancer that has spread to the brain from other places in the body.
Brainstem implant - auditory prosthesis that bypasses the cochlea and auditory nerve to help individuals who cannot benefit from a cochlear implant because the auditory nerves are not working.
Braxton-Hicks contractions - painless contractions during pregnancy that help the uterus to grow and to help the blood circulate through the uterus.
BRCA1 - a gene, which, when altered, indicates an inherited susceptibility to breast cancer.
BRCA2 - a gene, which, when altered, indicates an inherited susceptibility to breast and/or ovarian cancer.
Breast augmentation (also called augmentation mammaplasty) - a procedure to reshape the breast in order to make it larger. The procedure can also be performed to reconstruct the breast following breast surgery.
Breast cancer - a cancerous tumor of the breast tissue.
Breast conservation therapy - surgery to remove a breast cancer and a small amount of benign tissue around the cancer without removing any other part of the breast. These procedures include a lumpectomy or a partial (segmental) mastectomy.
Breast implant - a manufactured, silicone, rubber sac which is filled with sterile saline or silicone gel that is used for either breast augmentation or reconstruction.
Breast reconstruction - surgery to rebuild a breast mound following a mastectomy.
Breast self-examination (BSE) - a method in which a woman examines her breasts and the surrounding areas for lumps or changes. A BSE should be performed once a month, usually at a time other than the days before, during, or immediately after the menstrual period.
Breast specialist - term describing a health care professional who has a dedicated interest in breast health.
Breech birth - an abnormal delivery presentation in which the baby's feet, knees, or buttocks come into the birth canal first, before the baby's head.
Bromocriptine - a medication that acts on hormone-producing tumors to suppress its hormone-producing function. It is also used to treat other conditions.
Bronchiolitis - inflammation that involves the bronchioles (small airways).
Bronchitis - an inflammation of the mucous membranes of the bronchial tubes, causing a persistent cough that produces considerable quantities of sputum (phlegm).
Bronchodilators - a group of medications that widen the airways in the lungs.
Bronchoscopy - the examination of the bronchi (the main airways of the lungs) using a flexible tube (bronchoscope). Bronchoscopy helps to evaluate and diagnose lung problems, assess blockages, obtain samples of tissue and/or fluid, and/or to help remove a foreign body.
Bronchus - any of the larger air passages that connect the trachea to the lungs.
Bruise (also called contusion) - a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes discoloration and swelling in the area.
Bruxism - the condition of incessant grinding and clenching of the teeth, unintentionally, and at inappropriate times.
Budd-Chiari syndrome - a condition of the liver in which the veins that drain blood from the liver are blocked or narrowed.
Bulimia nervosa (also known as bulimia) - a disease in which there are uncontrolled episodes of overeating that are usually followed by purging (self-induced vomiting), misuse of laxatives, enemas, or medications that cause increased production of urine, fasting, and/or excessive exercise to control weight.
Bulking agents - laxatives that make bowel movements soft and easy to pass.
Bundle-branch block - a condition in which the heart's electrical system is unable to normally conduct the electrical signal.
Bunion - an inflammation and thickening of the bursa in the joint of the big toe.
Bursa - a sac filled with fluid located between a bone and a tendon or muscle.
Bursitis - repeated small stresses and overuse that cause the bursa to swell and become irritated.