Definition Byssinosis is a chronic, asthma-like narrowing of the airways. Also called brown lung disease, byssinosis results from inhaling particles of cotton, flax, hemp, or jute. Description Although inhaling cotton dust was identified as a source of respiratory disease more than 300 years ago, byssinosis has been recognized as an occupational hazard for textile workers for less than 50 years. More than...

Since 1980, bulimia nervosa has been recognized by the American Psychiatric Association as an autonomous eating disorder. The term bulimia means "an extreme hunger," but the word is most commonly understood to refer to Bulimia Nervosa. It is characterized by recurrent episodes of binge eating followed by such regular activities as self-induced vomiting, excessive use of laxatives and/or diuretics,...

Definition Buerger's disease is an inflammation of the arteries, veins, and nerves in the legs, principally, leading to restricted blood flow. Left untreated, Buerger's disease can lead to gangrene of the affected areas. Buerger's disease is also known as thromboangitis obliterans. Causes and symptoms The exact cause of Buerger's disease is not known. It is seen most often in young to middle-aged...

Definition Bronchiectasis is a condition in which an area of the bronchial tubes is permanently and abnormally widened (dilated), with accompanying infection. Description The bronchial tubes are the networks of branching tubes which deliver air to the tiny sacs of the lungs (alveoli). In bronchiectasis, the diameter of the bronchi is unusually large. Examination of the walls of the bronchial tubes reveals destruction...

Definition Breech birth is the delivery of a fetus (unborn baby) in a bottom- or foot-first position. Between 3 to 4 percent of fetuses start labor in the breech position, which is a potentially dangerous situation. Description Throughout most of pregnancy the developing fetus is completely free to move around within the uterus. Between 32 and 36 weeks, however, the fetus becomes so large that movement is restricted....

Definition Breast reduction is a surgical procedure performed to decrease the size of the breasts. Purpose Women with very large breasts (macromastia, or mammary hyperplasia) seek breast reduction for relief of back, shoulder, and neck pain. They may also feel uncomfortable about their breast size and have difficulty finding clothing that will fit properly. Additionally, breast reduction may be needed after...

Doctors recommend that women start to practice breast self-examination after their first menstrual period, and continue the habit monthly throughout their lives. Most doctors want their patients to learn the technique and will take the time to teach it, or will ask a nurse or physician's assistant to do so. Although breast cancer is rare in women under 30, it is useful for a woman to examine her breasts...

Definition Breast ultrasound (or sonography) is an imaging technique for diagnosing breast disease, such as cancer. It uses harmless, high-frequency sound waves to form an image (sonogram). The sound waves pass through the breast and bounce back or echo from various tissues to form a picture of the internal structures. It is not invasive and involves no radiation. Purpose Breast ultrasound may be used in several...

Definition A breast biopsy is removal of breast tissue for examination by a pathologist. This can be accomplished surgically, or by withdrawing tissue through a needle. Purpose A biopsy is recommended when a significant abnormality is found, either on physical examination and/or by an imaging test. Examples of abnormality can include a breast lump felt during physical self examination or tissue changes noticed...

Definition Breast implantation is a surgical procedure for enlarging, or augmenting, the breast. Implants are breast-shaped pouches that are saccular in shape, made of a silicone outer shell, and filled with silicone gel or saline (salt water), are used. Purpose Breast implantation is usually performed to make normal breasts larger for cosmetic purposes. Sometimes a woman having a breast reconstruction after...

Definition Breast reconstruction is a series of surgical procedures performed to recreate a breast. Reconstructions are commonly done after one or both breasts are removed as a treatment for breast cancer. Also, a breast may need to be refashioned for other reasons, such as trauma or abnormalities that occur during breast development. Purpose Many authorities consider reconstruction an integral part of the...

Definition A brain tumor is an abnormal growth of tissue in the brain. Unlike other tumors, brain tumors spread by local extension and rarely metastasize (spread) outside the brain. A benign brain tumor is composed of non-cancerous cells and does not metastasize beyond the part of the brain where it originates. A brain tumor is considered malignant if it contains cancer cells, or if it is composed of harmless...

Definition A bowel resection is a surgical procedure in which a part of the large or small intestine is removed. Purpose Bowel resection may be performed to treat various disorders of the intestine, including cancer, obstruction, inflammatory bowel disease, ruptured diverticulum, ischemia (compromised blood supply), or traumatic injury. Description The preferred type of bowel resection involves removal of the...

Breast cancer is a potentially dangerous tumor that develops in the cells of the breast. Cancer cells sometimes spread from the breast to other parts of the body. KEYWORDS for searching the Internet and other reference sources Mammography Oncology Tamoxifen In the United States, breast cancer is a very common cancer among women, second only to skin cancer. Breast cancer also occurs in men, but much more rarely....

Definition A brain biopsy is the removal of a small piece of brain tissue for the diagnosis of abnormalities of the brain, such as Alzheimer's disease, tumors, infection, or inflammation. Purpose By examining the tissue sample under a microscope, the biopsy sample provides doctors with the information necessary to guide diagnosis and treatment. Precautions Imaging of the brain is performed to determine...

Definition A bone scan is a diagnostic procedure used to evaluate abnormalities involving bones and joints. A radioactive substance is injected intravenously, and the image of its distribution in the skeletal system is analyzed to detect certain diseases or conditions. Purpose Bone scans are most frequently ordered to check whether a cancer that originated elsewhere has spread to the bones. Cancers that begin...

Definition Bowel preparation is a procedure usually undertaken before a diagnostic procedure or treatment can be initiated for certain colorectal diseases. Bowel preparation is a cleansing of the intestines from fecal matter and secretions. Purpose The ultimate goal of bowel preparation is to empty and cleanse the bowel for a diagnostic procedure (using x rays to detect a disease process in the intestines)...

Definition Brain abscess is a bacterial infection within the brain. Description The brain is usually well insulated from infection by bacteria, protected by the skull, the meninges (tissue layers surrounding the brain), the immune system, and the highly regulated barrier between the bloodstream and the brain. Under certain circumstances, however, bacteria can invade the brain and cause a localized infection...

Definition The bone marrow—the sponge-like tissue found in the center of certain bones—contains stem cells that are the precursors of white blood cells, red blood cells, and platelets. These blood cells are vital for normal body functions, such as oxygen transport, defense against infection and disease, and clotting. Blood cells have a limited life span and are constantly being replaced; therefore,...

Definition Bone x rays are a diagnostic test in which ionizing radiation passing through the bones being examined enables an image to be produced on film. Purpose Bone x rays are ordered to detect disease or injury to the bone such as broken bones, tumors, and other problems. They can determine bone density, texture, erosion, and changes in bone relationships. Bone x rays also evaluate the joints for diseases...

Definition Bowel training helps to reestablish normal bowel movements in persons who suffer from constipation, diarrhea, incontinence, or irregularity. Healthy bowel activity is considered one or two movements of moderate size every day. Purpose Many people for many reasons have irregular bowel function. In some cases, the irregularity lasts beyond the condition that caused it. The bowels by themselves develop...

Definition Bone growth stimulation is the technique of promoting bone growth in difficult to heal fractures by applying a low electrical current or ultrasound to the fracture. Purpose Bone growth stimulation is done when satisfactory healing is not occurring naturally or when the pace of healing is too slow. This condition is called fracture nonunion, and it occurs more frequently among adults than children,...

Definition Bone grafting is a surgical procedure that places new bone or a replacement material into spaces between or around broken bone (fractures) or in holes in bone (defects) to aid in healing. Purpose Bone grafting is used to repair bone fractures that are extremely complex, pose a significant risk to the patient, or fail to heal properly. Bone grafting is also used to help fusion between vertebrae,...

Definition Bone disorder drugs are medicines used to treat diseases that weaken the bones. Purpose The drugs described here are used to treat or prevent osteoporosis (brittle bone disease) in women past menopause as well as older men. They also are used prescribed for Paget's disease, a painful condition that weakens and deforms bones, and they are used to control calcium levels in the blood. Bone is living...

Definition A bone density test, or scan, is designed to check for osteoporosis, a disease that occurs when the bones become thin and weak. Osteoporosis happens when the bones lose calcium and other minerals that keep them strong. Osteoporosis begins after menopause in many women, and worsens after age 65, often resulting in serious fractures. These fractures may not only bring disability, but may affect longevity....

Definition Bone biopsy is the removal of a piece of bone for laboratory examination and analysis. Purpose Bone biopsy is used to distinguish between malignant tumors and benign bone disease such as osteoporosis and osteomyelitis. This test may be ordered to determine why a patient's bones ache or feel sore, or when a mass or deformity is found on an x ray, CT scan, bone scan, or other diagnostic imaging...

Definition Boils are bacterial infections of hair follicles and the surrounding skin that form pustules around the follicle. Boils are sometimes called furuncles. When several furuncles merge to form a single deep sore with several "heads," or drainage points, the result is called a carbuncle. Description Boils are firm, red swellings about 5–10 mm across that are slightly raised above the skin...

Definition Blood typing is a laboratory test done to determine a person's blood type. If the person needs a blood transfusion, another test called crossmatching is done after the blood is typed to find blood from a donor that the person's body will accept. Purpose Blood typing and crossmatching are most commonly done to make certain that a person who needs a transfusion will receive blood that matches...

blood sugar When we refer to ‘blood sugar’, we actually mean the monosaccharide (simple sugar) glucose dissolved in the blood. Maintaining a stable blood glucose concentration is necessary in order to keep it high enough to ensure normal functioning of the brain, whilst also preventing the harmful consequences which can arise when the concentration is too high. Blood glucose concentration in healthy...

Definition Blood sugar tests include several different tests that measure the amount of sugar (glucose) in a person's blood. These tests are performed either on an empty stomach, or after consuming a meal or pre-measured glucose drink. Blood sugar tests are done primarily to diagnose and evaluate a person with diabetes mellitus. Purpose The body uses sugar, also called glucose, to supply the energy it needs...

Definition A blood culture is done when a person has symptoms of a blood infection, also called bacteremia. Blood is drawn from the person one or more times and is tested in a laboratory to find and identify any microorganism present and growing in the blood. If a microorganism is found, more testing is done to determine the antibiotics that will be effective in treating the infection. Purpose Bacteremia is...

Definition A complete blood count (CBC) is a series of tests used to evaluate the composition and concentration of the cellular components of blood. It consists of the following tests: red blood cell (RBC) count, white blood cell (WBC) count, and platelet count; measurement of hemoglobin and mean red cell volume; classification of white blood cells (WBC differential); and calculation of hematocrit and red blood...

Definition A blood clot is a mass of blood cells and blood components that form to stop the bleeding that occurs when a blood vessel is injured. When a blood vessel is broken, platelets in the blood become sticky and clump together at the site of the injury. They begin to form a mass to stop the flow of blood. Description Clotting is the body's normal response to a bleeding injury. It is a necessary function...

Definition Bleeding varices are bleeding, dilated (swollen) veins in the esophagus (gullet), or the upper part of the stomach, caused by liver disease. Description Engorged veins are called varices (plural of varix). Varices may occur in the lining of the esophagus, the tube that connects the mouth to the stomach, or in the upper part of the stomach. Such varices are called esophageal varices. These varices...

Definition Bladder training is a behavioral modification treatment technique for urinary incontinence that involves placing a patient on a toileting schedule. The time interval between urination is gradually increased in order to train the patient to remain continent. Purpose Bladder training is used to treat urinary urge incontinence. Urge incontinence occurs when an individual feels a sudden need to urinate...

Definition Black lung disease is the common name for coal workers' pneumoconiosis (CWP) or anthracosis, a lung disease of older workers in the coal industry, caused by inhalation, over many years, of small amounts of coal dust. Description The risk of having black lung disease is directly related to the amount of dust inhaled over the years; the disease typically affects workers over age 50. Its common...

Definition Bladder stones are crystalline masses that form from the minerals and proteins, which naturally occur in urine. These types of stones are much less common than kidney stones. Description Bladder stones can form anywhere in the urinary tract before depositing in the bladder. They begin as tiny granules about the size of a grain of sand, but they can grow to more than an inch in diameter. These stones...

Definition Bladder cancer is a disease in which the cells lining the urinary bladder lose the ability to regulate their growth and start dividing uncontrollably. This abnormal growth results in a mass of cells that form a tumor. Description Bladder cancer attacks the urinary bladder, a hollow, muscular organ that stores the urine received from the kidneys until it is excreted out of the body. Bladder cancer...

Definition A bite is an injury caused by an animal, such as a mammal or insect, that breaks the skin. A sting is a puncture wound made by insects or marine animals. There is often a danger of infection from toxins or venom with bites and stings. Description In the United States, dogs surpass all other mammals in the number of bites inflicted on humans. Children face a greater risk than adults, and children...

Definition Birthmarks are areas of discolored and raised spots found on the skin. Birthmarks are groups of malformed pigment cells or blood vessels. Description Vascular birthmarks are benign (noncancerous) skin growths comprised of rapidly growing or poorly formed blood vessels or lymph vessels. Found at birth (congenital) or developing later in life (acquired) anywhere on the body, they range from faint spots...

Birth defects or congenital defects are those present at birth. They result from heredity, environmental influences, or maternal illness. Such defects range from the very minor, such as a dark spot or birthmark that may appear anywhere on the body, to more serious conditions that may result in marked disfigurement, impaired functioning, or decreased lifespan. A classification of structural defects can be as...

Definition Bird flu is an infectious disease caused by strains of the Type A influenza viruses that ordinarily only infect birds. Avian influenza A (H5N1) virus infected and caused the deaths of people. Description Bird flu, which is also known as avian influenza, was first identified in Italy more than 100 years ago. Avian viruses occur naturally in birds, and can infect birds including chickens, ducks, geese,...

Definition Bipolar disorders is the name given to a group of mental disorders characterized by extreme fluctuations in mood. People diagnosed with bipolar disorders experience moods ranging from deepest depression to mania, often with periods of less extreme moods, or even emotional stability, in between. Description Individuals diagnosed with bipolar disorders experience fluctuations in mood over which they...

Definition Biofeedback is a technique that uses monitoring instruments to measure and feed back information about muscle tension, heart rate, sweat responses, skin temperature, or brain activity. Terms associated with biofeedback include applied psychophysiology or behavioral physiology. It is also viewed as a mind-body therapy method used in complementary and alternative medicine. Biofeedback is an important...

Binge eating is out-of-control eating. A person with binge eating disorder exhibits a repetitive pattern of bingeing that often results in overweight or obesity*, “yo-yo dieting,” and guilty or embarrassed feelings. * obesity (o-BEE-si-tee) is an excess of body fat. People are considered obese if they weigh more than 30 percent above what is healthy for their height. Keywords for searching the...

Definition Bile duct cancer, or cholangiocarcinoma, is a malignant tumor of the bile ducts within the liver (intrahepatic), or leading from the liver to the small intestine (extrahepatic). It is a rare tumor with poor outcome for most patients. Description Bile is a substance manufactured by the liver that aids in the digestion of food. Bile ducts are channels that carry the bile from the liver to the small...

Definition The Bender Visual Motor Gestalt test (or Bender-Gestalt test) is a psychological assessment used to evaluate visual-motor functioning, visual-perceptual skills, neurological impairment, and emotional disturbances in children and adults ages three and older. Purpose The Bender-Gestalt is used to evaluate visual-motor maturity and to screen children for developmental delays. The test is also used to...

Definition Bedsores, also called decubitus ulcers, pressure ulcers, or pressure sores, begin as tender, inflamed patches that develop when a person's weight rests against a hard surface, exerting pressure on the skin and soft tissue over bony parts of the body. For example, skin covering a weight-bearing part of the body, such as a knee or hip, is pressed between a bone and a bed, chair, another body part,...

A condition created by sustained physical, sexual, and/or emotional abuse, which creates a variety of physical and emotional symptoms. Violence of any kind is traumatic to victims, and the thought that someone could exert extreme violence against a loved one or a child is repulsive. Battered-child syndrome and battered-spouse syndrome are both the result of repeated violence—beatings, choking, sexual...

What is bad breath? The culprits of bad breath are gram-negative anaerobic bacteria, microorganisms that live and function in an oxygen-deprived environment. These organisms naturally exist in the mouth, says Susanne Cohen. The bacteria ingest protein particles and metabolize them, producing sulfur gases. "That rotten-egg smell," says Swaroop. Bad breath Causes & symptoms Accumulation of plaque...