What is Stroke?

In the United States, stroke is the third leading cause of death and long- term disability in adults. There are about 600,000 new strokes each year. It is crucial for people to understand that a stroke, "brain attack", or cerebral vascular accident (CVA) is a medical emergency. Early treatment can reduce the damage caused by a stroke. However, people need to recognize the symptoms of a stroke and get to a hospital promptly. Immediate care can save lives and improve chances of a successful recovery!

A stroke occurs when the flow of blood and oxygen to the brain is cut off. This causes brain cells to die or become damaged. The cells injured by a stroke may control important body functions. A person may experience problems with movement, problems with thinking, problems with speaking, emotional problems, daily living problems, and pain. The longer the stroke is left untreated, the greater the number of affected brain cells.

The two main types of strokes are ischemic and hemorrhagic (bleeding) strokes. Ischemic strokes occur when a blood vessel in the brain or neck becomes blocked. This is the most frequent cause of stroke and is responsible for about 80 percent of all strokes. These blockages result from three conditions:

• After a clot has formed within a blood vessel in the brain or neck, called thrombosis.
• When a clot from another part of the body such as the heart has traveled to the brain or neck, called embolism.
• When fatty deposits (plaque) cause severe narrowing of an artery in or leading to the brain, called stenosis.

Hemorrhagic strokes occur when a blood vessel in the brain bursts and causes bleeding within or around the brain. The most common cause of this hemorrhage is high blood pressure. About 20 percent of strokes are hemorrhagic.