Definition of Stroke

What is a Stroke?

A stroke occurs when blood stops flowing to or inside the brain.^[1][2] This occurs either because in one of two ways. Either a blood clot stops flow in the brain or a blood vessel bursts and the part of the brain that that vessel supplied don't get fresh, oxygenated blood. The presence of leaking blood also kills brain cells. When a clot stops blood flow, it is called an ischemic stroke. This is the more common type of stroke. When a blood vessel breaks, it's called a hemorrhagic stroke. When a stroke is of short duration, it's called a transient ischemic attack or TIA.

Stroke is the third most common cause of death in the US and the leading cause of long-term disability.^[3][4] While the number of new cases of stroke has been decreasing over the last 50 years, the severity of stroke has not decreased. Currently, there are 750,000 new strokes each year in the United States.