Wondering what a stroke is and how to detect if you're having one?

We asked the National Institute on Neurological Disorders and Stroke for some answers to our questions.

We know: 1-Minute Lesson on Strokes

What is a stroke?

A stroke, sometimes called a "brain attack," occurs when blood flow to the brain is interrupted. When a stroke occurs, brain cells in the immediate area begin to die because they stop getting the oxygen and nutrients they need to function.

How common are strokes?

Stroke is the third leading cause of death in the United States and a leading cause of serious, long-term disability in adults. About 600,000 new strokes are reported in the U.S. each year.

What causes strokes?

There are two major kinds of stroke.

The first, called an ischemic stroke, is caused by a blood clot that blocks or plugs a blood vessel or artery in the brain. About 80 percent of all strokes are ischemic.
The second, known as a hemorrhagic stroke, is caused by a blood vessel in the brain that breaks and bleeds into the brain. About 20 percent of strokes are hemorrhagic.

What are the symptoms of a stroke?

The symptoms of stroke are distinct because they happen quickly:

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

What should a bystander do?

If you believe someone is having a stroke - if he or she suddenly loses the ability to speak, or move an arm or leg on one side, or experiences facial paralysis on one side - call 911 immediately.

Stroke is a medical emergency. Every minute counts when someone is having a stroke. The longer blood flow is cut off to the brain, the greater the damage. Immediate treatment can save people's lives and enhance their chances for successful recovery.

Why is there a need to act fast?

Ischemic strokes, the most common type of strokes, can be treated with a drug called t-PA, that dissolves blood clots obstructing blood flow to the brain. The window of opportunity to start treating stroke patients is three hours, but to be evaluated and receive treatment, patients need to get to the hospital within 60 minutes.

What disabilities can result from a stroke?

Although stroke is a disease of the brain, it can affect the entire body. The effects of a stroke range from mild to severe and can include paralysis, problems with thinking, problems with speaking, and emotional problems. Patients may also experience pain or numbness after a stroke.

What can I do to prevent a stroke?

The best treatment for stroke is prevention. There are several risk factors that increase your chances of having a stroke:

High blood pressure
Heart disease
Smoking
Diabetes
High cholesterol

If you smoke - quit. If you have high blood pressure, heart disease, diabetes, or high cholesterol, getting them under control - and keeping them under control - will greatly reduce your chances of having a stroke.