What are risk factors?

Risk factors are behaviors or traits that make you more likely to develop a disease or condition. Having one or more risk factors does not mean that you definitely will develop a condition, only that you are more likely to do so.

More than 795,000 people suffer from stroke in the U.S. each year, but up to 50% of all strokes are preventable. Stroke is the leading cause of disability in the United States. Many of the risk factors can be treated, modified or managed. However, some risk factors for stroke cannot be changed.

Factors that can be managed

  • Hypertension, or high blood pressure, is the single most important risk factor for stroke. A blood pressure of 140/90 or above in adults is considered to be high. The usual target for blood pressure treatment in adults is to keep the blood pressure at 120/80 or below.
  • Smoking remains the most important preventable cause of premature death in the country. If you smoke, quit, and if you don’t smoke, don’t start. Look for smoking cessation resources in your community.
  • Heart disease, especially atrial fibrillation (a type of irregular heartbeat), is a significant risk factor for stroke. If you have heart disease, carefully follow your treatment plan.
  • Diabetes mellitus increases stroke risk, especially for strokes due to damage to small blood vessels. The usual target for management is an HbA1c of <7% or a fasting blood sugar of 80-120 mg/dL.
  • High cholesterol (also called hyperlipidemia) increases the risk of stroke. Have your cholesterol level checked and manage your cholesterol level, if necessary, by limiting the amount of fat and cholesterol you eat. The target level of low-density lipoproteins (LDL), the “bad” cholesterol, is less than 70 mg/dL.
  • Alcohol (more than one drink per day) is associated with stroke risk. Limit the amount of alcohol you drink.
  • Having overweight/obesity and leading a sedentary lifestyle may increase your risk of developing hypertension and diabetes, two risk factors for stroke.
  • Existing carotid and/or coronary artery disease. The carotid arteries in your neck supply most of the blood to your brain. A carotid artery that has been damaged by fatty build-up of plaque inside the artery wall may become blocked by a blood clot, causing a stroke.
  • Illegal drug use. Street drugs, such as crack, cocaine, and marijuana have been shown to increase the risk of stroke. Some of these drugs directly affect the blood vessels in the brain causing a stroke. Others cause damage to the heart, which can lead to stroke.

Unmanageable risk factors

  • Age: People of all ages, including children, have strokes. However, the risk of stroke increases as age increases.
  • Biological sex: 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, women account for more than half of all stroke deaths. People who are pregnant have a higher stroke risk. Also at higher risk are people who take birth control pills and who also smoke or have risk factors such as high blood pressure.
  • Race: The risk of stroke varies with race and ethnicity. People who are Black and Hispanic are more likely to have strokes than people who are white. The risk of stroke is also high among people who are Native American and Alaskan Native.
  • Family history: Your stroke risk is greater if a parent, grandparent, sister, or brother has had a stroke.
  • Prior stroke or heart attack: A person who has already had a stroke or heart attack is at much higher risk of having a second stroke.

Your doctor can evaluate your risk for stroke and help you manage your risk factors. Regular check-ups are important in detecting problems before they become serious.

If you would like to learn more, you might want to visit our stroke risk calculator at this website: my.clevelandclinic.org/stroke-risk-calculator

Last reviewed by a Cleveland Clinic medical professional on 07/11/2018.


  • American Heart Association/American Stroke Association. About Stroke: Understanding Risk (http://www.strokeassociation.org/STROKEORG/AboutStroke/Understanding-Risk_UCM_308539_SubHomePage.jsp) Accessed 7/11/2018.
  • National Institute of Neurological Disorders & Stroke. Brain Basics: Preventing Stroke (http://www.ninds.nih.gov/disorders/stroke/preventing_stroke.htm) Accessed 7/11/2018.
  • National Stroke Association. Am I at risk for a stroke? (https://www.stroke.org/en/about-stroke/stroke-risk-factors) Accessed 7/11/2018.

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