What is a stroke?

A stroke is a life-threatening event in which part of the brain is deprived of adequate oxygen. A stroke can cause oxygen-starved brain cells to die within minutes, and damage can continue for several days afterward. The condition must be treated immediately. A stroke is also known as a cerebrovascular accident or a "brain attack."

How dangerous is a stroke?

Strokes are extremely dangerous, accounting for more than 160,000 deaths each year, according to the Centers for Disease Control and Prevention. Stroke is the third leading cause of death in the United States, behind heart disease and cancer. It is also a leading cause of adult disability and institutionalization. Each year, about 700,000 people suffer strokes. Of those, 500,000 are first-time strokes.

Are all strokes the same?

No. There are two kinds of strokes. An ischemic stroke occurs when the blood supply to the brain is interrupted, usually by a blood clot. These clots may be caused by "hardening of the arteries" in the carotid arteries, which feed the head and brain with oxygen-rich blood. The second kind of stroke is a hemorrhagic stroke, which occurs when there is bleeding into or around the brain. Strokes can also have a variety of severities.

What is the difference between a "mini-stroke" and a "little stroke?"

A transient ischemic attack or "mini-stroke" is different from a "little stroke." A mini-stroke tends to produce transient symptoms of stroke without causing permanent damage because the oxygen flow to the brain is only temporarily interrupted. Whereas, a little stroke will cause permanent damage, but only in a very small part of the brain.