About the Hennepin

Stroke Center

Info for Health

Professionals

Info for Patients

What Causes a Stroke?

A stroke is caused when a blood vessel clogs or bursts, preventing blood flow to the brain. Without a way to get oxygen and nutrients from the blood vessel, brain cells die.

The majority of strokes, about 85%, are called ischemic strokes. These are strokes caused by clots. Clots typically form in an artery in the brain. Arteries in the brain are more likely to experience clots when they have been damaged by fatty buildups, called atherosclerosis. Clots also can happen when a clot forms somewhere else in the body, travels through the bloodstream and then gets stuck in a narrowed artery in or near the brain. Atrial fibrillation (an abnormal heart rhythm) is a condition which may cause blood clots in the heart, which can then travel up to the brain.

About 15% of strokes are called hemorrhagic strokes. These are strokes caused when an artery in the brain bursts. These strokes can be caused by severely high blood pressure, a head injury or by aneurysms (blood-filled pouches that balloon out from weak parts of the artery.) Aneurysms are often caused or made worse by high blood pressure.

Reducing Your Risk for a Stroke

High blood pressure, atherosclerosis (fatty buildups in the arteries), and atrial fibrillation (which may cause blood clots in the heart that can travel to the brain) are all conditions that can contribute to a stroke. That’s why the National Stroke Association recommends the following guidelines to help prevent strokes:

1. Know your blood pressure. If you’re blood pressure is high, work with your doctor to keep it under control. Have your blood pressure checked at least once per year or more often if you have high blood pressure.
2. Find out if you have atrial fibrillation (AF). Your doctor can detect AF by carefully checking your pulse. If you have it, work with your doctor to help manage it.
3. If you smoke, stop. Smoking doubles the risk of stroke.
4. If you drink alcohol, drink it in moderation. There is some evidence that having one drink per day may lower your risk for stroke if there are no other medical reasons why you shouldn’t drink. Remember that alcohol is a drug and can interact with other drugs you’re taking in harmful ways. If you don’t drink, don’t start.
5. Know your cholesterol number. If it’s high, work with your doctor to lower it. Often, high cholesterol can be controlled with diet and exercise. Some people may require medication, too.
6. If you have diabetes, work with your doctor to control it. Your doctor can work with you on the best diet, lifestyle, and medicines to help manage your diabetes.
7. Exercise. Include exercises you enjoy in your daily routine. As little as 30 minutes of brisk exercise a day can help reduce your risk of stroke.
8. Enjoy a low-salt, low-fat diet. A low-salt, low-fat diet can help reduce your blood pressure and risk of stroke.
9. Ask your doctor if you have circulation problems. If you do, work with your doctor to control them.

Information adapted from American Stroke Association and National Stroke Association.