Definition Peritonitis is an inflammation of the membrane which lines the inside of the abdomen and all of the internal organs. This membrane is called the peritoneum. Description Peritonitis may be primary (meaning that it occurs spontaneously, and not as the result of some other medical problem) or secondary (meaning that...

Definition Gyne refers to female, and mastia refers to the breast. Gynecomastia is strictly a male disease and is any growth of the adipose (fatty) and glandular tissue in a male breast. Not all breast growth in men is considered abnormal, just excess growth. Causes and symptoms Breast growth is directed exclusively by female hormones—estrogens. Although men have some estrogen in their system,...

Definition Gulf War syndrome describes a wide spectrum of illnesses and symptoms ranging from asthma to sexual dysfunction that have been reported by U.S. and U.S. allied soldiers who served in the Persian Gulf War in 1990–91. Description Between 1994 and 1999, 145 federally funded research studies on Gulf War-related illnesses were undertaken at a...

Definition Infection occurs when the parasitic guinea worm resides within the body. Infection is not apparent until a pregnant female worm prepares to expel embryos. The infection is rarely fatal, but the latter stage is painful. The infection is also referred to as dracunculiasis, and less commonly as dracontiasis. Description Before the early 1980s, guinea worms...

Guillain-Barre syndrome (GBS) is an acquired inflammatory, neurological disorder in which the immune system of the human body attacks portions of the body’s peripheral nervous system. The organization National Institute of Neurological Disorders and Stroke (NINDS) classifies GBS as asyndrome rather than as a disease because no known disease-causing agent is associated with GBS. Also called...

Definition Guided imagery is the use of relaxation and mental visualization to improve mood and/or physical well being. Benefits The connection between the mind and physical health has been well documented and extensively studied. Positive mental imagery can promote relaxation and reduce stress , improve mood, control high blood pressure, alleviate pain , boost...

Definition Growth hormone tests measure the levels of specific hormones that regulate human growth. These hormone levels are measured in blood serum samples obtained by venipuncture. To studygrowth hormone function under specific conditions, certain medications may be administered before blood is taken and hormone levels are measured. Human growth hormone (hGH)...

The simultaneous treatment of several clients who meet regularly under the guidance of a therapist to obtain relief from particular symptoms or to pursue personal change. Group therapy has numerous advantages over individual therapy. The therapist's knowledge about the clients offers an added dimension through the opportunity of observing them interact with each other. Clients are helped by...

  Definition Granuloma inguinale is a sexually transmitted infection that affects the skin and mucous membranes of the anal and genital areas. Its name is derived from granuloma, a medical term for a mass or growth of granulation tissue, and inguinale, a Latin word that means located in the groin. Granulation tissue is tissue formed during wound healing that is rich in blood capillaries...

Definition Graft-vs.-host disease is an immune attack on the recipient by cells from a donor. Description The main problem with transplanting organs and tissues is that the recipient host does not recognize the new tissue as its own. Instead, it attacks it as foreign in the same way it attacks germs, to destroy it. If immunogenic cells from the donor are transplanted along with the organ...

Definition Gout drugs are medicines that prevent or relieve the symptoms of gout, a disease that affects the joints and kidneys. Purpose Gout is a disease in which uric acid, a waste product that normally passes out of the body in urine, collects and forms crystals in the joints and the kidneys. When uric acid crystals build up in the joints, the tissue around the joint becomes inflamed,...

  Definition Gout is a form of acute arthritis that causes severe pain and swelling in the joints. It most commonly affects the big toe, but may also affect the heel, ankle, hand, wrist, or elbow. Attacks of gout usually come on suddenly, stop after five to 10 days, and can keep recurring. Description Gout is different from other forms of arthritis because it occurs when there...

Definition An uncommon and life-threatening hypersensitivity disorder believed to be an autoimmuneprocess related to antibody formation in the body. Goodpasture's syndrome is characterized by renal (kidney) disease and lung hemorrhage. Description The disorder is characterized by autoimmune reaction which deposits of antibodies in...

Definition Gonorrhea is a highly contagious sexually transmitted disease (STD) caused by the Neisseria gonorrhoeae bacterium. The genitourinary tract is the main system that is usually affected, but gonorrhea can also spread to the rectum, the throat, and the eyes. Left untreated, gonorrhea can spread through the bloodstream and infect the brain, heart valves, joints, and the reproductive...

Definition Goiter refers to any visible enlargement of the thyroid gland. Description The thyroid gland sits astride the trachea (windpipe) and is shaped like a butterfly. It makes thyroxin, a hormone that regulates the metabolic activity of the body, rather like the gas pedal on a car. Too much thyroxin increases the metabolism, causing weight loss, temperature elevation, nervousness, and irritability....

Definition Glycosylated hemoglobin is a test that indicates how much sugar has been in a person's blood during the past two to four months. It is used to monitor the effectiveness of diabetes treatment. Purpose Diabetes is a disease in which a person cannot effectively use sugar in the blood. Left untreated, blood sugar levels can be very high. High sugar levels increase risk of complications,...

Definition Glycogen is a form of stored glucose that the body uses as an energy source. Glycogen storagedisease (GSD) involves defects that cause an abnormal accumulation of glycogen, usually found in the liver, muscle, or both. When accumulation occurs in the liver, glycogen storage diseases result in liver enlargement and in conditions ranging from mild hypoglycemia to liver...

  Definition Glucose-6-phosphate dehydrogenase deficiency is an inherited condition caused by a defect or defects in the gene that codes for the enzyme, glucose-6-phosphate dehydrogenase (G6PD). It can cause hemolytic anemia, varying in severity from life-long anemia, to rare bouts of anemia to total unawareness of the condition. The episodes of hemolytic anemia are...

  Definition Acute glomerulonephritis is an inflammatory disease of both kidneys predominantly affecting children from ages two to 12. Chronic glomerulonephritis can develop over a period of 10-20 years and is most often associated with other systemic disease, including diabetes, malaria, hepatitis, orsystemic lupus erythematosus. Description Acute glomerulonephritis is...

Definition Glaucoma is a group of eye diseases that damage the optic nerve and gradually cause vision loss. Description The optic nerve, located at the back of the eye, consists of more than a million of nerve fibers that carry images from the retina to the brain. Glaucoma damages optic nerve fibers, with the result that blind spots develop in the visual field. If the entire nerve is destroyed,...

Description Korean ginseng is one of the most widely used and acclaimed herbs in the world. Its scientific name is Panax ginseng, which is the species from which Chinese, Korean, red, and white ginseng are produced. Chinese and Korean ginseng are the same plant cultivated in different regions, and have slightly different properties...

  Definition Ginkgo biloba is an herbal remedy that has been utilized for thousands of years in China and elsewhere. It is obtained from the leaves and seeds of a plant that is commonly known as the maiden hair tree, believed to be the oldest living species of tree. Purpose Ginkgo preparations have been used to treat such conditions as asthma, inflammation, dizziness, memory problems, and...

Definition Giardiasis is a common intestinal infection spread by eating contaminated food, drinkingcontaminated water, or through direct contact with the organism that causes the disease, Giardia lamblia. Giardiasis is found throughout the world and is a common cause of traveller's diarrhea. In the United States it is a growing problem, especially among children in childcare centers. Description Giardia is...

Definition GI bleeding studies uses radioactive materials in the investigation of bleeding from the gastrointestinal (GI) tract. These studies go under various names such as "GI bleeding scans" or "Tagged red blood cell scans." They are performed and interpreted by radiologists (physicians who specialize in diagnosis and treatment of diseases by...

Definition Gestational diabetes is a condition that occurs during pregnancy. Like other forms of diabetes,gestational diabetes involves a defect in the way the body processes and uses sugars (glucose) in the diet. Gestational diabetes, however, has a number of characteristics that are different from other forms of diabetes. Description Glucose is a form of sugar...

Definition Gestalt therapy is a humanistic therapy technique that focuses on gaining an awareness ofemotions and behaviors in the present rather than in the past. The therapist does not interpret experiences for the patient. Instead, the therapist and patient work together to help thepatient understand him/herself. This type of therapy focuses on experiencing the presentsituation rather than talking about what...

Definition Genital warts, or condylomata acuminata, are also called venereal warts. These warts are painless, pink or grayish growths on the skin and mucous membranes of the genitals and anal area. They are usually found in clusters. Genital warts are very contagious and spread through sexual contact with an infected person. Description Genital warts are the most...

Definition Genital herpes (herpes genitalis) is a highly contagious sexually transmitted disease (STD) caused by a strain of the herpes simplex virus (HSV). Genital herpes invades the body through mucous membranes, also known as small breaks in the skin. Description Genital herpes is characterized by pain, itching, and sores (i.e., blister-like lesions)...

Definition A genetic test examines the genetic information contained inside a person's cells, called DNA , to determine if that person has or will develop a certain disease or could pass a disease to his or her offspring. Genetic tests also determine whether or not couples are at a higher risk than the general population for having a child affected with a genetic disorder. Purpose Some...

Definition Generalized anxiety disorder is a condition characterized by "free floating" anxiety or apprehension not linked to a specific cause or situation. Description Some degree of fear and anxiety is perfectly normal. In the face of real danger, fear makes people more alert and also prepares the body to fight or flee (the so-called "fight or flight"...

General surgery is the treatment of injury, deformity, and disease using operative procedures. Purpose General surgery is frequently performed to alleviate suffering when a cure is unlikely through medication alone. It can be used for routine procedures performed in a physician’s office, such as vasectomy, or for more complicated operations requiring a...

Definition General adaptation syndrome, or GAS, is a term used to describe the body's short-term and long-term reactions to stress. Stressors in humans include such physical stressors as starvation, being hit by a car, or suffering through severe weather. Additionally, humans can suffer such emotional or mental stressors as the loss of a loved one, the inability to solve a problem,...

Definition General adaptation syndrome, or GAS, is a term used to describe the body's short-term and long-term reactions to stress. Stressors in humans include such physical stressors as starvation, being hit by a car, or suffering through severe weather. Additionally, humans can suffer such emotional or mental stressors as the loss of a loved one, the inability to solve a problem,...

Gene therapy is a rapidly growing field of medicine in which genes are introduced into the body to treat diseases. Genes control heredity and provide the basic biological code for determining a cell's specific functions. Gene therapy seeks to provide genes that correct or supplant the disease-controlling functions of cells that are not, in essence, doing...

Definition Also known as sex change surgery or sex reassignment surgery, gender reassignment surgery is a procedure that changes a person's external genital organs from those of one gender to those of the other. Purpose There are two reasons commonly given for altering the genital organs: ·         Newborns with intersex deformities must early on be assigned...

Definition Gender identity disorder is a condition characterized by a persistent feeling of discomfort or inappropriateness concerning one’s anatomic sex. The disorder typically begins in childhood withgender identity disconnects and is manifested in adolescence or adulthood by a person dressing in clothing associated with the desired gender, as opposed to one’s...

Definition Lesbian, gay, bisexual, and transgender (LGBT) individuals are as diverse as the generalpopulation in terms of race, ethnicity, age, religion, education, income, and family history.A number of health concerns are unique to or shared by the LGBT community, however, including...

Definition Gaucher disease is a rare genetic disorder that results in accumulation of fatty molecules called cerebrosides. It can have serious effects on numerous body organs including the liver, spleen, bones and central nervous system. Treatments based on molecular biology are becoming available, but are very expensive. Description Gaucher disease was first described by the French physician...

Definition Gastrostomy is a surgical procedure for inserting a tube through the abdomen wall and into the stomach. The tube, called a "g-tube," is used for feeding or drainage. Purpose Gastrostomy is performed because a patient temporarily or permanently needs to be fed directly through a tube in the stomach. Reasons for feeding by gastrostomy include birth defects of the mouth,...

Definition Gastroenteritis is a catchall term for infection or irritation of the digestive tract, particularlythe stomach and intestine. It is frequently referred to as the stomach or intestinal flu,although the influenza virus is not associated with this illness. Major symptoms include nausea...

Definition Gastritis commonly refers to inflammation of the lining of the stomach, but the term is often used to cover a variety of symptoms resulting from this inflammation, as well as symptoms of burning or discomfort. True gastritis comes in several forms and is diagnosed using a combination of tests. In the 1990s, scientists discovered that the main cause of most gastritis is infection...

Definition Gastrinomas are tumors associated with a rare gastroenterological disorder known as Zollinger-Ellison syndrome (ZES). They occur primarily in the pancreas and duodenum (beginning of the small intestine) and secrete large quantities of the hormone gastrin, triggering gastric acid production that produces ulcers. They may be malignant (cancerous) or benign. Description Gastrinomas are an integral part...

Definition A gastric emptying scan (GES) is an x-ray exam using special radioactive material that allows physicians to identify abnormalities related to emptying of the stomach. Diseases that involve changes in the way the stomach contracts (motility disorders) are best diagnosed by this test. Purpose The study is used most frequently to evaluate patients who have symptoms suggestive...

Definition Gastric acid determination, also known as stomach acid determination, gastric analysis, or basal gastric secretion, is a procedure to evaluate gastric (stomach) function. The test specifically determines the presence of gastric acid, as well as the amount of gastric acid secreted. It is often done in conjunction with the gastric acid stimulation...

Definition Gastrectomy is the surgical removal of all or part of the stomach. Purpose Gastrectomy is performed for several reasons, most commonly to remove a malignant tumor or to cure a perforated or bleeding stomach ulcer. Description Gastrectomy for cancer Removal of the tumor, often with removal of surrounding lymph nodes, is the only curative treatment for various forms of gastric (stomach) cancer. For...

Definition Gas embolism, also called air embolism or arterial gas embolism, is the presence of gas bubbles in the bloodstream that obstruct circulation. Description Gas embolism may occur with decompression from increased pressure. It typically occurs in ascending divers who have been breathing compressed air. If a diver does not fully exhale upon ascent, the air...

Definition Gangrene is the term used to describe the decay or death of an organ or tissue caused by alack of blood supply. It is a complication resulting from infectious or inflammatory processes, injury, or degenerative changes associated with chronic diseases, such as diabetes mellitus. Description Gangrene may be caused by a variety of chronic diseases and post-traumatic, post-surgical, and...

Definition A ganglion is a small, usually hard bump above a tendon or in the capsule that encloses a joint. Aganglion is also called a synovial hernia or synovial cyst. Description A ganglion is a non-cancerous cyst filled with a thick, jelly-like fluid. Ganglions can develop on or beneath the surface of the skin and usually occur between the ages of 20 and 40. Most ganglions...

Definition Gammaglobulin is a type of protein found in the blood. When gammaglobulins are extracted from the blood of many people and combined, they can be used to prevent or treat infections. Purpose This medicine is used to treat or prevent diseases that occur when the body's own immune system is not effective against the disease. When disease-causing agents enter the body, they normally trigger the...

Definition A gallstone is a solid crystal deposit that forms in the gallbladder, which is a pear-shapedorgan that stores bile salts until they are needed to help digest fatty foods. Gallstones canmigrate to other parts of the digestive tract and cause severe pain with life-threatening complications. Description Gallstones vary in size and chemical structure. A gallstone may be as tiny as a grain...