Glossary

Find definitions for thousands of medical terms, treatments, and tests -- even health-related abbreviations, prefixes, and suffixes.

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Gallstones are small stones that form in the gallbladder or the bile ducts, the tubes that carry bile to the small intestine. They usually don't cause symptoms unless they block the opening to the gallbladder. If that happens, you may have pain in the upper right part of your belly.

If you have a bad attack, or a second attack, you may want to have your gallbladder removed because you are likely to have more attacks.

Last Revised: September 27, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Arvydas D. Vanagunas, MD - Gastroenterology

Gangrene is the death and decay of tissue that usually occurs when the blood supply to the tissue is cut off by injury or infection. After the tissue is dead, bacteria may infect the tissue and cause decay.

Gangrene may affect small areas, such as fingers or toes that have been frostbitten, or larger areas of tissue, such as part of the foot. People who have impaired blood flow, such as people with diabetes, may be at higher risk of gangrene if they have skin wounds and infections that are not treated promptly.

Gangrene is treated by restoring blood flow to the affected area, treating any infection, and removing the dead and dying tissue. If it is severe, gangrene sometimes requires that a part of the body, such as a finger, toe, or foot, be amputated.

Last Revised: October 12, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Dennis L. Stevens, MD, PhD - Internal Medicine, Infectious Disease

Reflux means that stomach acid and juices move back up into your esophagus, the tube that leads from the throat to the stomach. This can cause heartburn, ulcers, and damage to your esophagus. When you have heartburn that bothers you often, it's called gastroesophageal reflux disease, or GERD.

You can treat GERD with lifestyle changes, like quitting smoking and making changes in your diet to avoid foods that make your heartburn worse. Your doctor may also suggest medicines.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Peter J. Kahrilas, MD - Gastroenterology

Gastroparesis is a disorder in which the stomach takes too long to empty after eating. The delay is caused by damage to the stomach nerves and results in bloating, heartburn, and possibly serious symptoms because digestion is altered.

Diabetes is the most common cause of gastroparesis. Other causes include some disorders of the nervous system, such as Parkinson's disease and stroke, and some medicines, such as tricyclic antidepressants, calcium channel blockers, and narcotics.

The most common symptoms of gastroparesis are:

  • A feeling of fullness after only a few bites of food.
  • Nausea.
  • Vomiting.
  • Food coming back up your throat, without nausea or vomiting.

Symptoms range from mild to severe. Severe symptoms of gastroparesis may improve with treatment using medicines that help with nausea and vomiting (antiemetics) and medicines that help the stomach empty more quickly (motility agents). In very severe cases, a feeding tube placed in the small intestine may be needed.

Last Revised: July 19, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Arvydas D. Vanagunas, MD - Gastroenterology

A gene is a section of the genetic material or deoxyribonucleic acid (DNA) in a cell. Genes, alone or in combination, determine what features (genetic traits) a person inherits from his or her parents, such as blood type, hair color, eye color, and other characteristics, including risks for certain diseases.

Many genes together make up chromosomes. Defects in genes or chromosomes may cause changes in certain body processes or functions. These changes may be undetectable or may cause genetic diseases, such as hemophilia or Down syndrome. Genetic problems may also increase the risk for some conditions, such as juvenile idiopathic arthritis and depression.

Gene changes (mutations) can be passed from parents to children. Diseases that run in families are often caused by genetic defects. A person may be born with a certain genetic makeup that makes him or her susceptible or at risk for a certain condition.

Last Revised: November 29, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Siobhan M. Dolan, MD, MPH - Reproductive Genetics

Anesthesia is a way to control pain using anesthetic medicine. General anesthesia, which can be injected into a vein or inhaled, affects the entire body and makes the person unconscious.

A person under general anesthesia is completely unaware of what is going on and does not feel pain during the surgery or procedure. Anesthesia interrupts the pain signals between a person's nerve endings and the brain. The health professional administering the anesthesia (anesthesiologist or nurse anesthetist) monitors the person's condition throughout the procedure.

Last Revised: September 30, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD, MD - Family Medicine & John M. Freedman, MD, MD - Anesthesiology

General practitioners are medical doctors who diagnose and treat most types of health conditions or diseases and do not specialize in any particular area of medicine. They provide basic medical service for males and females of all age groups.

General practitioners usually complete a 1- to 2-year residency following medical school. There is no board certification for general practitioners.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Anesthesia is a way to control pain using anesthetic medicine. Anesthetics are used to numb a specific area of the body (local and regional anesthesia) or to cause a person to sleep through a painful procedure such as surgery (general anesthesia).

  • Local anesthesia numbs just a small area of tissue where a minor procedure is to be done.
  • Regional anesthesia affects a larger (but still limited) part of the body and does not make the person unconscious. Spinal and epidural anesthesia are examples of regional anesthesia.
  • General anesthesia affects the entire body and makes the person unconscious. The unconscious person is completely unaware of what is going on and does not feel pain from the surgery or procedure. General anesthesia medicines can be injected into a vein or inhaled.

The type of anesthesia used depends upon the procedure and the person's health, age, and preferences. Young children usually cannot remain still during surgery and need general anesthesia. People with certain health problems choose local or regional anesthesia when that is an option, because it may pose fewer risks than general anesthesia in some situations. Long or difficult surgeries may require general anesthesia.

A person choosing local or regional anesthesia needs to be able to lie still and remain calm during the surgery and will likely be given medicine to help with relaxation.

Last Revised: September 30, 2011

Author: Healthwise Staff

Medical Review: Adam Husney, MD, MD - Family Medicine & John M. Freedman, MD, MD - Anesthesiology

The generic name is the chemical name of a medicine. This name is the same no matter how many companies manufacture the medicine.

When a company makes a medicine, they give it a brand name (or trade name). A generic name medicine can be made by more than one company. And each company may have their own brand name for the same generic name medicine. So there can be more than one brand name for each generic name. Generic names and brand names of medicines are chemically the same. But generic name medicines are usually less expensive. A doctor may be able to prescribe a generic name medicine if it is available and appropriate.

Last Revised: March 9, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Theresa O'Young, PharmD - Clinical Pharmacy

Genetic disorders are diseases that can be passed from parents to children. Some disorders may be inherited if only one parent has the abnormal gene, while others can be inherited only if both parents have the abnormal gene.

If one or both parents have a defective gene or have a genetic disorder, the risk of passing the disorder on to a child is the same with each pregnancy. Having one healthy or one affected child doesn't change the odds that future children will or will not be affected.

If the baby's mother or father or anyone in either of their families has a genetic disorder, genetic counseling may help the family decide what type of prenatal testing they want.

Genetic disorders that may be inherited include:

  • Cystic fibrosis.
  • Sickle cell disease.
  • Tay-Sachs disease.
  • Thalassemia.
  • Hemophilia.
  • Duchenne muscular dystrophy.
  • Huntington's disease.
  • Polycystic kidney disease.

A small number of disorders occur because of a one-time mistake in a single gene (new mutation), such as a change in a gene of one of the parents' egg or sperm cells or because of a change in a gene of the fetus. These one-time genetic changes are unlikely to happen again in future pregnancies.

Last Revised: November 3, 2011

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Siobhan M. Dolan, MD, MPH - Reproductive Genetics

Gestational diabetes is a type of diabetes that some women get during pregnancy.

You treat it by making certain eating changes, exercising, checking blood sugar levels, and possibly taking insulin shots. With treatment, most women who have gestational diabetes will have healthy babies.

Gestational diabetes usually goes away after the baby is born.

Last Revised: September 26, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine

Giant cell arteritis (GCA), or temporal arteritis, is an inflammation of the blood vessels that carry blood up through the neck to the head (carotid arteries) and those that carry blood within the head, especially those in the side of the face near the temple. This condition can cause irreversible blindness if not treated promptly.

Giant cell arteritis is the result of the body's immune system reacting against itself, known as an autoimmune response. It mostly affects people older than age 50. Giant cell arteritis causes a headache that begins as a dull, throbbing pain on one side of the head around the eye or near the temple. Occasionally the pain may feel like a stabbing or burning sensation. It may also cause jaw pain and loss of vision or blindness.

A large number of people with giant cell arteritis also have a condition called polymyalgia rheumatica (PMR), which causes muscle pain and morning stiffness—most commonly in the shoulders and pelvic area—along with fever, weight loss, and a general feeling of being unwell.

Giant cell arteritis is usually treated with corticosteroid medicine. This disease usually responds to treatment, with symptoms decreasing within 2 to 7 days. Medicine may be needed for 1 to 2 years or more to prevent symptoms from returning.

Last Revised: April 13, 2011

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Stanford M. Shoor, MD - Rheumatology

Glaucoma is a group of eye diseases that damage the optic nerve at the back of your eye. This can cause vision loss. Although the cause of glaucoma isn't clear, experts think it's often related to a buildup of pressure in the eye.

Glaucoma can be easily detected during regular eye exams. It usually responds well to treatment with medicine.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Adam Husney, MD - Family Medicine & Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology

Glucagon is a hormone produced by the pancreas that causes the liver to release its stored sugar into the bloodstream. Glucagon is also available as a prescription medicine that comes in prefilled vials and syringes and works in the same way as the natural hormone.

People with diabetes or hypoglycemia sometimes develop very low blood sugar levels. If a person has a very low blood sugar level and is unconscious, or if the person cannot or will not drink or eat something containing sugar, he or she needs a glucagon shot.

Instructions for how to give a glucagon shot should be kept with the medicine. The expiration date should be checked often, as most glucagon kits need to be replaced every 6 months. The shot should be given by someone who knows how to give it correctly. A person who is having a low blood sugar emergency can safely have more than one glucagon shot. Make sure the person's blood sugar is checked after giving the glucagon shot. If the person becomes more alert, carefully give a quick-sugar food or liquid.

Last Revised: September 20, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Jennifer Hone, MD - Endocrinology, Diabetes and Metabolism

Gout is a form of arthritis caused by a buildup of uric acid crystals in a joint. It causes sudden attacks of pain, swelling, redness, and stiffness, usually in one joint. It happens most often in the big toe.

Gout usually comes on without a cause. But drinking alcohol (especially beer), eating seafood and red meat, or taking certain medicines, such as aspirin or some diuretics, can also trigger an attack of gout.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Nancy Ann Shadick, MD, MPH - Internal Medicine, Rheumatology