Medical Dictionary: G

gain: A hearing aid’s power, measured in the number of decibels that it can add to sound.

gait cycle: A description of the movement of your feet and legs while you walk, beginning when one heel strikes the ground and ending when that heel strikes the ground again a few seconds later.

galactogogue: An agent that promotes breast milk production.

gamma-aminobutyric acid (GABA): Chief inhibitory neurotransmitter in the brain. As an inhibitory neurotransmitter, it instructs the next neuron not to fire. GABA may help quell anxiety.

ganglion cyst: a benign, fluid-filled cyst commonly found on the back of the wrist or elsewhere on the hand.

gastritis: Inflammation of the stomach.

gene therapy: Correction of a genetic defect by replacing it with a normal gene.

genetic: Referring to genes or inherited characteristics.

geriatric care manager: A professional who assists older people and families facing challenging care decisions and whose training may include social work, counseling, nursing, or gerontology.

geriatrician: A physician who specializes in the care of older patients.

gestational diabetes mellitus: A form of diabetes that has its onset during pregnancy, usually in the last trimester.

giant-cell arteritis: A condition involving inflammation of blood vessels; causes headache and sometimes leads to blindness.

glaucoma: A condition in which an abnormal buildup of the fluid in the eye (aqueous humor) or disruption of its natural flow places increasing pressure on the optic nerve and other delicate structures.

glaucoma: A disorder characterized by excessive fluid pressure within the eyeball; can occur as a complication of diabetes.

glomerular filtration rate (GFR): The rate at which your kidneys filter excess water and other wastes; a test by the same name is used to determine how well your kidneys are functioning.

glucagon: A hormone produced by the alpha cells of the pancreas that increases the concentration of glucose in the blood.

glucocorticoids: A class of hormones released by the adrenal gland during the stress response. Glucocorticoids are steroid hormones, affecting inflammation, blood pressure, and metabolism.

glucose: The body’s chief source of energy; a simple sugar that passes easily from the digestive tract into the bloodstream when you consume carbohydrates.

glutamate: A neurotransmitter that may play a role in mood disorders and schizophrenia.

glycemic index: A scale for evaluating foods, based on the rate at which sugar is absorbed into the bloodstream after eating a specific food.

glycemic load: A calculation of the glycemic index multiplied by the actual amount of carbohydrate in a serving of food and divided by 100. This value gives a more accurate picture of how much a food can affect blood sugar. Foods with a high glycemic load are thought to increase the risk of insulin resistance and other health problems.

glycosylated hemoglobin test: A blood test that reflects average blood sugar levels over the preceding two to three months by measuring the amount of glucose adhering to hemoglobin, a protein in red blood cells. The product formed by the attachment of glucose to hemoglobin is known as HbA1c.

goiter: An enlarged thyroid gland that creates a lump protruding from the neck. It is commonly found when the thyroid produces too much or too little thyroid hormone.

gout: A form of arthritis caused by abnormal accumulation of uric acid, usually in the metatarsophalangeal joint at the base of the big toe.

graft: A scientific word for transplant.

gram (g): A metric unit of weight equivalent to one-thousandth of a kilogram.

Graves’ disease: An autoimmune disease that causes the thyroid gland to overproduce thyroid hormone.

ground fault circuit interrupter: A device that protects against electrical shock; usually installed in an electrical outlet.

guardianship: A legal process during which a person is judged incompetent to make decisions about health care, finances, or other important issues and a guardian or conservator is appointed.