Glossary

Health Terms beginning with "G"

Galactosemia

A genetic defect that causes intolerance to galactose, a common sugar found in dairy products. Treatment consists of keeping galactose out of the diet. If untreated, the disorder can lead to severe infections in infants, cataracts and mental retardation.

Gallstones

Crystal-like deposits of various sizes that develop in the gallbladder—a small, pear-shaped organ that stores bile, a digestive juice produced by the liver. Gallstones are more common in people who are obese or have lost a lot of weight in a short amount of time. Gallstones that are simply floating around inside the gallbladder generally cause no symptoms and no harm. If the gallstone becomes lodged within the cystic duct, a small conduit that connects the gallbladder to another tube called the common bile duct, you will feel pain in the upper right abdomen, possibly extended to the upper back, and you may experience nausea, indigestion or fever.

Galvanic skin response training

Measures changes in your skin's surface, particularly perspiration rates. The galvanic skin response is a change in how the skin conducts electricity, triggered by an emotional stimulus such as fright. The biofeedback method is commonly used to deal with stress, phobias and stuttering.

Gamete intrafallopian transfer (GIFT)

Uses the same stimulation process as in vitro fertilization, except eggs and sperm are combined and immediately returned to the fallopian tube so that fertilization may occur naturally. This procedure, which requires a laparoscopy, is only available to women who have normal fallopian tube function. GIFT procedures usually require general anesthesia.

Ganglion

The term for a group of nerve cells outside the central nervous system. The sacral ganglion is the most common nerve tissue to which genital herpes retreats.

Gangrene

Tissue death caused by poor blood flow. The tissue usually turns black and often has a foul odor.

Gastroesophageal reflux disease (GERD)

A condition that causes the stomach's digestive juices to back up or "reflux" into the esophagus, the passageway for food from the mouth to the stomach.

Gastrointestinal

Something that affects the stomach and intestine.

Gastrointestinal tract

The organs of the digestive system, from the mouth to the anus, including the stomach and intestines.

Gatekeeper

The primary care physician or other professional whom a patient must see for all initial medical visits. For referrals to all specialists, diagnostic, therapeutic, or hospital services, the patient must see the gatekeeper first. This approach is used by many health maintenance organizations.

Gene

A segment of DNA that contains the instructions for making a specific protein.

Gene expression

The process of translating the DNA sequence of the gene in the nucleus to a usable protein in the cell.

Generalized anxiety disorder (GAD)

An excessive or unrealistic worry that is unrelated to another illness and can last six months or more.

Generalized seizures

Seizures that result from abnormal neuronal activity in many parts of the brain. These seizures may cause loss of consciousness, falls or massive muscle spasms.

Genetic counseling

An individual or family concerned about a genetic disorder or considering genetic testing should attend at least one genetic counseling session. The counseling includes education about genetics, the disease and the test in question. The counselor takes a detailed family history and provides information about the probability that the disease is inherited. Patients learn about the availability of testing, what the results mean, and the health care management options for positive, uncertain and negative results.

Genetic predisposition

The potential for an individual to develop a condition or trait because of its presence in a family member.

Genetics

The scientific study of the mechanisms by which traits are passed from generation to generation through genes.

Genetic screening

Genetic testing that aims to identify persons at above-average risk of having a particular genetic disease or being a carrier of that disease.

Genetic test

A procedure that examines some aspect of a person's genetic makeup, either directly through gene sequencing or indirectly through the measure of marker chemicals. Such a test usually aims to determine whether a person is at above-average risk of having a disease-causing genetic mutation or is a carrier for such a mutation.

Genital or uterine prolapse

When the ligaments that support a woman's pelvic organs lose their supportive ability. This decline in strength can occur with age, estrogen deficiency, as a result of obesity, and/or after multiple childbirths when ligaments and muscles are stretched and weakened. Once pelvic support is weakened, pelvic organs may sag, causing pelvic pressure, urinary incontinence, and rectal discomfort.

Genome

The full complement of nuclear DNA comprises the genome. Most cells contain a copy of the full genome in the nucleus (exceptions include red blood cells, which lack a nucleus).

Geriatric care manager

A health care professional (often a social worker) who has training and experience working with older people and their families and helps them deal with the challenges of aging.

Gestational diabetes mellitus

A type of diabetes mellitus that can occur when a woman is pregnant. In the second half of the pregnancy, the woman may have glucose (sugar) in the blood at a higher-than-normal level. When blood sugar is high, the baby may grow too large, possibly creating difficulty passing through your birth canal. However, when the pregnancy ends, the blood glucose levels return to normal in about 95 percent of all cases.

Gingivitis

A condition in which gums swell, turn red and bleed easily.

Gingko biloba

An herbal extract made from a flowering tree native to China. Studies suggest it can enhance memory.

Glaucoma

A group of diseases that can lead to damage to the eye's optic nerve (which carries images from the eye to the brain) and result in blindness.

Glomerulations

Pinpoint bleeding caused by recurrent irritation.

Glomeruli

Plural of glomerulus.

Glomerulonephritis

Inflammation of the glomeruli, most often caused by an autoimmune disease, but sometimes resulting from infection.

Glomerulosclerosis

Scarring of the glomeruli. It may result from diabetes mellitus (diabetic glomerulosclerosis) or from deposits in parts of the glomerulus (focal segmental glomerulosclerosis). The most common signs of glomerulosclerosis are proteinuria and kidney failure.

Glomerulus

A tiny set of looping blood vessels in the nephron where blood is filtered in the kidney.

Glucocorticoids

These drugs may be used to relieve scleroderma-related pericarditis (inflammation of the membrane surrounding the heart) and myositis (inflammation of the muscles).

Glucose

A simple sugar, also known as dextrose, found in the blood that is the end product of metabolized carbohydrates. It is the brain's and body's main source of energy, so measuring how much glucose is used is a good indicator of the brain's activity level.

Glucose tolerance

Your body's ability to appropriately use blood glucose, which is manufactured when you eat carbohydrates. Impaired glucose tolerance (IGT) refers to a condition in which blood sugar levels are higher than normal but are not high enough to be classified as diabetes. IGT is a major risk factor for type 2 diabetes.

Glucose tolerance test (GTT)

Refers to the test that allows doctors to see how your body handles sugar over a period of time. It's used to determine if you have low blood sugar.

Gluten

A component of wheat and some other grains. Intolerance to it is associated with the disease gluten-sensitive enteropathy or celiac disease.

GnRH agonists

Gonadotropin-releasing hormone. This is a class of hormones that has been shown to relieve endometriosis by blocking estrogen production that stimulates its growth. GnRH agonists can cause side effects including menopausal symptoms triggered by estrogen deprivation, such as hot flashes, vaginal dryness and some bone loss. Hormone replacement therapy (HRT), a combination of estrogen and progestin hormones, typically is prescribed to alleviate these side effects so that treatment with GnRH agonists can continue for six months or longer, if necessary. However, the safety of HRT for both short-term and long-term use is under intense scrutiny by the federal government as result of risks identified by several major studies conducted in 2002.

Goiter

An abnormal swelling of the thyroid gland.

Gonadotropin

Injectable medication used to induce ovulation in PCOS women attempting pregnancy if clomiphene or insulin sensitizing drugs fail. Also called menotropins, menopausal gonadotropin or urofollitropin.

Gonioscopy

A visual examination of the angle where the cornea and the iris meet inside the eye. This exam uses a special lens containing a mirror placed lightly on the front of the eye so the health care professional can see inside.

Gonorrhea

A sexually transmitted disease, characterized by an unusual discharge from the vagina for women and painful urination or penile discharge for men.

Gout

A joint disease caused by high levels of uric acid in the blood.

Gram's stain

A method of identifying bacteria by staining a specimen with dye and using a microscope to observe the cell. This test is used to identify gonorrhea bacteria but is only positive in about half of all cases in women, so it cannot be used alone as a definitive diagnosis.

Grave's disease

A disorder of the thyroid caused by antibodies in the blood that stimulate growth of the thyroid and the overproduction of thyroid hormone. It's also known as diffuse toxic goiter.

Group insurance

A group of people are insured by the same company at the same time, which is less risky to the insurance company; therefore this type of insurance is usually less expensive than an individual policy.

Guaranteed renewable policy

Also called a noncancellable policy, an individual health insurance policy under which you can't be singled out for cancellation of coverage. You will receive individual insurance under that policy as long as you pay your premium. Your premium can go up. However, the Health Insurance Portability Act requires that all policies are renewable except for those with limited benefits or short-term policies.

Guru

A yoga master, teacher and guide. Translated from the Sanskrit meaning "darkness to light."

Gynecologist

A physician who specializes in diseases of the female genital tract and the reproductive physiology of women.