Stroke kills over 160,000 Americans each year. It is also a leading cause of long-term disability in adults, and the #1 reason why people are admitted to nursing homes.

Most Americans know that stroke is common, but they may not know much else about the disease. Unfortunately, this is a case in which ignorance costs lives. This is because a clot-busting drug treatment called tPA can dissolve stroke-causing clots and thus help decrease the terrible long-term effects of stroke in many people — but only if it is given as soon as possible after the stroke occurs.

In many cases, people who could benefit from tPA never receive it, because the people around them did not recognize the symptoms of a stroke and did not seek medical care immediately.

To address this problem, Lewis Morgenstern, M.D., and colleagues at the University of Michigan Stroke Program have created a test for people to take in order to find out how much they know about stroke.

When you have a spare couple of minutes, take the test. Hopefully, by the time you finish, you will have learned enough about stroke to know what to do in case you or someone you are with suffers a possible stroke.

Question 1: What is a stroke?

It's a brain emergency, just as a heart attack is a heart emergency.

Dr. Morgenstern explains: "A stroke is what happens in the brain when blood does not get to a part of the brain, and that part of the brain dies."

Question 2: Are all strokes the same?

No. Most are caused by blocked blood vessels in the brain, but some are caused by bleeding in the brain. No matter what the cause, strokes are emergencies that can kill or disable someone within hours.

Question 3: Are some people "destined" to have a stroke?

No. There's a lot you can do throughout life to reduce your risk.

Dr. Morgenstern explains: "Stroke is the most preventable of all catastrophic conditions."

Question 4: What are the signs that someone is having a stroke?

Any sudden changes in thinking, feeling, moving, speaking, understanding or seeing.

Dr. Morgenstern explains: "By definition, stroke symptoms occur suddenly and can come and go. The most common symptoms are sudden onset of weakness or numbness on one side of the body, difficulty in speaking or understanding, and losing vision in an eye, like a shade coming down from above in one eye. Strokes can also cause unexplained clumsiness, make a person drop objects, or cause someone to fall."

Question 5: What should you do if you think you, or someone near you, is having a stroke?

Call 911 immediately.

Dr. Morgenstern explains: "A stroke is a brain attack, and the faster a person gets diagnosed and treated, the better their chances will be. Don't wait, don't call your doctor's office first, don't drive yourself to the hospital. Don't think that it's not a stroke just because you don't have any of the risk factors. Get an ambulance, and fast."

Question 6: Does having a stroke mean you're definitely going to die or be disabled?

Not necessarily. Improved treatments are giving more people a chance to walk out of the hospital with minimal problems.

Dr. Morgenstern explains: "A percentage of the 720,000 Americans who suffer a stroke each year will die within hours or days after it occurs. And for those who survive it can be very disabling. But a sizable percentage of patients who have a stroke recover enough to function independently."

Question 7: Do only elderly people have strokes?

No. Although the risk of a stroke goes up with age, people of any age can suffer strokes.

Question 8: What are the factors that make someone more likely to have a stroke?

High blood pressure, smoking, diabetes, being overweight, having an abnormal heart-rhythm condition or other heart disease, or being related to someone who has had a stroke are all risk factors for stroke.

Dr. Morgenstern explains: "The number one risk factor is hypertension, or high blood pressure. People who have atrial fibrillation, which is a very common form of abnormal heart rhythm, also have a high stroke risk. Smoking is an important risk factor. Family history is important. People who are overweight, especially if they also have problems with blood sugar, blood pressure, and cholesterol, have a higher risk. And of course, people who have had a stroke or a "mini stroke," also called a TIA, have a much higher risk."

Question 9: What can people do to cut their stroke risk?

Quit smoking, lose weight, exercise more, get your blood pressure and cholesterol checked, and keep your blood-sugar levels under control if you have diabetes.