According to a Gallup survey, 17 percent of adults over 50 cannot name a single stroke symptom.

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Well, May is Stroke Awareness Month, and doctors are aiming to inform.

Stroke: The Definition

A stroke, otherwise known as a cerebral vascular accident or CVA, occurs in the brain when a blood clot blocks a blood vessel or when a blood vessel breaks, thus interrupting blood flow to an area of the brain.

This then kills brain cells in the immediate area. Doctors call this area of dead cells an infarct. These cells usually die within minutes or a few hours after the stroke starts.

What happens when these cells die?

When brain cells die, control of the abilities that the area of the brain once controlled are lost. This includes functions such as speech, movement, and memory.

The specific abilities lost or affected depend on where in the brain the stroke occurs and the size of the stroke.

What are the most common stroke symptoms?

Sudden numbness or weakness of face, arm, or leg -- especially on one side of the body.
Sudden confusion, trouble speaking or understanding.
Sudden trouble seeing in one or both eyes.
Sudden trouble walking, dizziness, loss of balance or coordination.
Sudden severe headache with no known cause.

These symptoms are a medical emergency, and you need to call 911 if you see or have any of these symptoms. Treatment can be more effective if given quickly; every minute counts.

What are major risk factors for strokes?

High blood pressure.
An abnormal heart rhythm, called atrial fibrillation.
Smoking.
Alcohol.
High cholesterol.
Diabetes.
Lack of regular exercise.
High sodium (salt) and a high-fat diet.
Circulation problems.

To find out if you are at risk for a stroke, visit www.stroke.org to take the test.