Research A-Z

Stroke

Definition

The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. Symptoms of a stroke depend on the area of the brain affected.

An ischemic stroke occurs when a blood clot forms, usually in the heart or neck arteries, and blocks the passage of blood to part of the brain. This type of stroke is most common.