Biology of a Stroke

Stroke is an injury to the brain that occurs when the blood supply to a part of the brain is interrupted. When this happens, the brain cells in that area may be damaged or die because they do not get enough oxygen and nutrients.

Unlike other cells in the body, brain cells do not replace themselves. Since the brain controls almost everything that the body does, bodily functions controlled by the damaged part of the brain can be affected. Changes may be physical, such as being unable to speak or having difficulty with movement of the arms or legs. Changes in behavior or mood may also reflect brain injury.

There are two major types of strokes:

Ischemic strokes make up almost 80% of all strokes and are caused by a blockage of a blood vessel in the brain or neck.

Hemorrhagic stroke is caused by the rupture of a blood vessel within the brain or on the brain's surface.

Most strokes occur as a result of degenerative changes in the body's blood vessels. The chance of having a stroke increases with age. Approximately 70% of all strokes occur in people age 65 or older. The risk of stroke doubles with every decade after age 55.

Over 750,000 Americans have a new or recurrent stroke every year. It is estimated that in the United States, a person has a stroke every 43 seconds of every day.

Stroke ranks as:

  • the leading disabler of adult Americans
  • the leading cause of discharge from hospitals to nursing homes
  • the second leading cause of dementia
  • the third leading cause of death

More women die of stroke than breast cancer.

Stroke can happen to anyone at any age, even children and babies. It is estimated that every year, the number of people under the age of 40 who have a stroke equals all the people killed in traffic accidents in the USA that year.

Risk Factors

Everyone has some stroke risk, but some people are more at risk than others. Know the most common risk factors for stroke and control those that you can:

  • High blood pressure - the leading cause of stroke
  • Heart disease - especially atrial fibrillation
  • Diabetes
  • Smoking
  • Previous stroke, mini-stroke or transient ischemic attack (TIA)
  • High cholesterol
  • Blockage of blood vessels in the neck
  • Alcohol/drug abuse
  • Use of oral contraceptives
  • Age
  • Family history of stroke
  • Race - African-Americans and Hispanics have a higher incidence of stroke
  • Blood disorders and blood vessel malformations
  • Anticoagulant therapy
  • Genetic disorders

Reducing Risk

Prevention of stroke begins with you. Know the most common risk factors for stroke and control those that you can.

Visit with your physician about how to reduce your risk of stroke. Lifestyle changes, medications, and in some cases, even surgery may be needed.

Educating yourself about the signs and symptoms of stroke can help save a life. For more information about signs and symptoms visit www.StrikeOutStroke.org.