What Is Stroke?

Stroke is literally a "brain attack", caused when the vital supply of blood and oxygen is cut off to part of the brain. If a portion of the brain loses its supply of nutrient-rich blood and oxygen, the bodily functions controlled by that part of the brain (vision, speech, walking, etc.) are impaired. Like a heart attack, every minute counts in getting a stroke victim emergency medical treatment so that brain damage and possible future disability will be minimized.

Colored CT image of the brain, purple area on right of image indicates stroke

Stroke is the third leading killer in the U.S. (after heart disease and cancer) and a primary cause of disability in adults. Each year more than 500,000 people in the U.S. have strokes, killing almost 150,000 of them and dramatically changing the lives of those who survive. Currently, three million Americans are permanently disabled because of stroke. However, new methods of stroke diagnosis and treatment are available, and they are dramatically increasing a person's chance of recovery after a stroke.

The National Stroke Association uses the term "brain attack" to describe stroke and to say that:

• Stroke affects the brain, perhaps the body's most vital organ
• Stroke strikes suddenly, often with no warning
• Stroke is a medical emergency and requires immediate care

Updated: January 14, 2008