Dictionary of Medical Terms

Gain a better understanding of medical terminology by searching our dictionary of more than 1,300 terms.

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All terms that start with the letter G

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giantism

Abnormal growth of the body due to an excessive amount of growth hormone produced by the pituitary gland.
giardiasis

A diarrheal illness caused by infection with Giardia lamblia, a parasitic protozoan.
gingiva

The gums.
gingivitis

Inflammation of the gums.
gland

An organ that releases a chemical. Endocrine glands are ductless and secrete hormones directly into the bloodstream. Exocrine glands secrete…
glaucoma

An eye disease, characterized by increased pressure within the eye, that can result in blindness if not treated.
glomerulonephritis

When the filtering units in the kidneys, called the glomeruli, are damaged, the kidneys don’t function properly and waste and…
glossitis

Inflammation of the tongue.
glucose

Dextrose. A simple six-carbon sugar naturally found in fruits, honey and blood.
goiter

Enlargement of the thyroid gland.
gonad

A sex gland (ovary or testis).
gonorrhea

A highly contagious, sexually transmitted bacterial disease of the genital/urinary system.
gout

A form of arthritis caused by deposits of uric acid crystals in the joints, usually the feet, hands and, especially,…
graft

A piece of skin or other tissue used as a transplant.
Gram's stain

A stain used as the first step in identifying bacteria.
grand mal

A major epileptic seizure characterized by convulsions, unconsciousness and sometimes loss of urinary or bowel continence. Usually followed by a…
Graves' disease

Overactive thyroid gland function (hyperthyroidism). Sometimes associated with protrusion of the eyes.
groin

The region of the body where the thigh and lower abdomen meet.
Guillain-Barre syndrome

A rare but reversible reaction to a viral illness or immunization that causes partial to complete loss of movement of…
gynecology

The branch of medicine that deals with the study and treatment of reproductive diseases in women.
gynecomastia

Overdevelopment of male breast tissue. Usually benign and temporary.