Risk Factors

Several factors increase your risk of stroke. The more risk factors you have, the greater your chance of having a stroke. Some you cannot control, such as age, family health history, race and gender. But you can modify, treat or control many factors to lower your risk of stroke.

What Are the Risk Factors for Stroke You Cannot Change?

  • Increasing Age. Stroke happens to people of all ages, even children, but the older you are, the greater your risk for stroke.
  • Gender. Stroke is more common in men than in women. In most age groups, more men than women will have a stroke in a given year. However, more than half of total stroke deaths occur in women. Overall, more women than men die of stroke. Use of birth control pills and pregnancy pose special stroke risks for women.
  • Heredity and Race. Your risk of stroke is greater if a parent, grandparent, sister or brother has had a stroke. African-Americans have a much higher risk of death from a stroke than Caucasians do. In part, this is because African-Americans have higher risk of diabetes, high blood pressure and obesity.
  • Prior Stroke or Heart Attack. The risk of stroke for someone who has already had one is many times that of a person who has not. If you have had a heart attack, you are also at higher risk of having a stroke.

What Risk Factors Can You Control or Treat with a Doctor's Help?

In some cases, people with health conditions described here can control them with changes in diet and exercise while others may need medication. Find out whether you have any of these conditions and follow your health care provider's advice.

  • High Blood Pressure. High blood pressure, or hypertension, is the most important risk factor for stroke. It's called the "silent killer," because it usually has no symptoms. High blood pressure (in an adult) is defined as a systolic pressure (top number) of 140 mm Hg or greater and/or a diastolic pressure (bottom number) of 90 mm Hg or greater that stays high over time. A blood pressure of less than 120 over 80 is considered normal in adults.
  • Diabetes. Diabetes mellitus is controllable, but having it greatly increases the risk of stroke. People with diabetes often also have high blood pressure, high blood cholesterol and are overweight, increasing their risk even more. Diabetes mellitus is defined as a fasting plasma glucose (blood sugar) of 126 mg/dL or more measured on two occasions.
  • Carotid or Other Artery Disease. The carotid arteries in your neck supply blood to your brain. A carotid artery narrowed by fatty deposits from artherosclerosis may become blocked by a blood clot. Peripheral artery disease is the narrowing of blood vessels carrying blood to leg and arm muscles. People with peripheral artery disease have a higher risk of carotid artery disease, which raises their risk of stroke.
  • Atrial Fibrillation or Other Heart Disease. Atrial Fibrillation (AF) is an important, treatable stroke risk factor. In AF, the heart's upper chambers quiver instead of beating effectively. This lets the blood pool and clot. If a clot breaks off, enters the bloodstream and lodges in an artery supplying blood to a part of the brain, a stroke results. People with coronary disease or heart failure have more than twice the risk of stroke as those with hearts that work normally. Dilated cardiomyopathy (an enlarged heart), heart valve disease and some types of congenital heart defects also raise the risk of stroke.
  • Transient Ischemic Attacks (TIAs). TIAs, sometimes called "mini-strokes," produce stroke-like symptoms that last less than 24 hours, but more commonly last only a few minutes to two hours. They are strong risk factors and predictors of stroke. Don't ignore TIAs—call 911 to get medical attention right away.
  • High Blood Cholesterol. A high level of total cholesterol in the blood (240 mg/dL or higher) is a major risk factor for heart disease, which raises your risk of stroke. Recent studies show that high levels of LDL "bad" cholesterol (greater than 100 mg/dL) and triglycerides (blood fats) directly increase the risk of stroke in people with prior coronary heart disease, ischemic stroke or transient ischemic attack (TIA). High levels of HDL "good" cholesterol (40 mg/dL or more) lower your risk of heart disease and stroke. People with a low level of HDL cholesterol (less than 40 mg/dL) have a higher risk of heart attack and stroke.
  • Tobacco Use. People who smoke cigarettes or cigars have a much higher risk of having a stroke. Even if you don't smoke, constant exposure to other people's tobacco smoke also increases your risk. Using birth control pills and smoking cigarettes greatly increases stroke risk. When you stop smoking - no matter how long or how much you have smoked - your risk of stroke quickly drops.
  • Physical Inactivity. Physical inactivity increases the risk of heart disease, which raises the risk of stroke. Regular physical activity helps reduce your risk of heart disease, heart attack and stroke. Do what you can to make your life more active for a total of at least 30 minutes on all or most days of the week.
  • Obesity. If you have too much fat, especially in the waist, you are at higher risk for health problems, including high blood pressure, high blood cholesterol, high triglycerides, diabetes, heart disease and stroke. To lose weight, you need to burn more calories than you take in. You can do this by eating healthy foods in reasonable amounts and becoming more active.
  • Excessive Alcohol. An average of more than one alcoholic drink a day for women or more than two drinks a day for men raises blood pressure and can lead to stroke.
  • lllegal Drugs. Intravenous drug abuse carries a high risk of stroke from cerebral embolism, a clot or other particle that lodges in the brain. Cocaine use has been linked to strokes and heart attacks; some strokes have been fatal even in first-time cocaine users.

Know the Warning Signs of Stroke

If you see someone experiencing any of the following stroke symptoms, call 911. Seeking treatment immediately can prevent disability. The warnings signs include:

  • Trouble speaking
  • Trouble seeing
  • Trouble walking
  • Weakness or numbness on one side
  • Sudden severe headache with no known cause

Call 9-1-1

If you see someone experiencing stroke symptoms, call 9-1-1. Seeking treatment immediately can prevent disability.