Updated June 10, 2015.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Definition:

A condition that is created in the body when there are more free radical atoms and/or molecules than antioxidants to neutralize them.

Cigarette smoking causes free radical production in the body and, at the same time, depletes antioxidants, putting smokers at risk for oxidative stress.

Oxidative stress may play a part in developing chronic health conditions like cancer, heart disease and diabetes.

See also: Smoking and Vitamin Depletion