Stroke: Symptoms and Risk Factors

Stroke, or cerebrovascular accident (CVA), is the third leading cause of death in the United States, resulting in more than 150,000 deaths per year.

About 80 percent of strokes are caused by a decrease in blood flow to the brain (called ischemic strokes). This is usually the result of a blood clot that has formed within an artery to the brain or has formed elsewhere (e.g., the heart) and traveled to a brain artery, where it has become lodged. Loss of blood flow can also occur if the heart malfunctions and no longer pumps blood effectively. Strokes can also be caused by a break in a blood vessel, causing blood to flow into the brain, compressing and damaging brain tissue. These are referred to as hemorrhagic strokes.

Stroke types

The most common causes of stroke are hypertension and atherosclerosis. In both cases, these result in damage to the arteries that feed the brain with blood and oxygen.

Symptoms

Symptoms of a stroke can be mild or severe and may include:

• Numbness or weakness of the face, arm, or leg, usually on one side of the body
• Confusion
• Difficulty speaking or understanding
• Visual disturbances, which may include partial or complete blindness
• Dizziness
• Severe headache with no known cause

A transient ischemic attack (TIA) is a “mini–stroke.” The symptoms are similar to those of a stroke, but a TIA usually lasts only 30 to 60 minutes. Although TIAs are not as serious as strokes, they can be a warning sign of an oncoming stroke.

Risk Factors

• Race: African–Americans and Latinos have a higher risk of stroke. However, it is unclear whether this increased risk is due to genetic factors.
  
• Age: The risk of stroke increases with age, especially after age 55.
  
• Gender: Women have a slightly higher risk than men.
• Smoking: Cigarette smoking increases the risk for stroke significantly.
• Underlying medical diseases: People with hypertension, diabetes, elevated cholesterol, atrial fibrillation, and narrowing (stenosis) of the carotid arteries that lead to the brain have a significantly increased risk of stroke. These disorders should be prevented or treated appropriately.
  
• Drug and alcohol abuse, especially cocaine abuse.
  
• Poor nutrition: High–fat, high–sodium diets and a lack of key nutrients, such as folic acid, have been associated with an increased risk for stroke (see Nutritional Considerations).
• Sedentary lifestyle: People who rarely engage in physical activity have an increased risk of stroke.