What Is a Stroke?

Understanding Your Body

Understanding Your Body provides easy-to-understand explanations of body systems and disease conditions. This material can be used for patient education, life sciences curriculum development, or to enhance public understanding of general health concepts. Permission for such use is not required, but citation as to source is requested. The information provided is derived from Consumer Versions of Clinical Practice Guidelines, sponsored by the Agency for Health Care Policy and Research, from 1992 to 1996.

A stroke is a type of brain injury. Symptoms depend on the part of the brain that is affected. People who survive a stroke often have weakness on one side of the body or trouble with moving, talking, or thinking.

Most strokes are ischemic (is-KEE-mic) strokes. These are caused by reduced blood flow to the brain when blood vessels are blocked by a clot or become too narrow for blood to get through. Brain cells in the area die from lack of oxygen. In another type of stroke, called hemorrhagic (hem-or-AJ-ic) stroke, the blood vessel isn't blocked; it bursts, and blood leaks into the brain, causing damage.

Strokes are more common in older people. Almost three-fourths of all strokes occur in people 65 years of age or over. However, a person of any age can have a stroke.

A person may also have a transient ischemic attack (TIA). This has the same symptoms as a stroke, but only lasts for a few hours or a day and does not cause permanent brain damage. A TIA is not a stroke but it is an important warning to help prevent an actual stroke in the future.

A stroke may be frightening to both the patient and the family. It helps to remember that stroke survivors usually have at least some spontaneous recovery or natural healing and often recover further with rehabilitation.

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Current as of November 2007
Internet Citation: What Is a Stroke?: Understanding Your Body. November 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/patients-consumers/prevention/understanding/bodysys/edbody8.html