Dictionary of Medical Terms

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

Filter By Alphabet

All terms that start with the letter I

Sort By:

indigestion

Upper abdominal discomfort usually experienced after a meal due to incomplete digestion.
induration

The process of hardening. An abnormally hard spot.
infarct

An area of dead or dying tissue produced by lack of blood flow to or from that area. For example,…
infection

Causing disease, especially by the presence of foreign microorganisms in the body, including bacteria, viruses or parasites.
infectious disease

A disease that can be spread from one person to another.
infertility

Inability to produce children.
inflammation

Swelling, redness, warmth and pain. A body tissue’s protective response to injury.
influenza

A contagious and infectious respiratory illness usually occurring in the winter.
ingrown nail

Edges of the nail become trapped under the skin, causing inflammation and, sometimes, infection.
injection

A fluid introduced into the body by a syringe and needle.
innate

Inborn, hereditary.
inoculation

The injection of a disease agent into the body to cause a mild form of the disease and build…
inoperable

Not curable through surgery.
insanity

Any form or degree of mental disturbance or unsoundness of mind, permanent or temporary, that makes a person incapable of…
insemination

To deposit sperm in the vagina.
insomnia

An inability to fall asleep or to remain asleep.
insulin

The hormone produced by the pancreas for regulating carbohydrate metabolism. Used in the treatment of diabetes mellitus.
integument

Skin.
intercourse

The exchange of communication between individuals. Sexual intercourse is the sexual joining of two people; coitus.
intestine

The tube involved in digestion and extending from the stomach to the anus. Consists of the small intestine and the…
intoxication

Poisoning, or the state of being affected by a poisonous substance. Often used to describe drunkenness.