What is a Stroke?

A stroke is an acute neurologic injury resulting from problems with blood flow to the brain. Approximately 80 percent of strokes are due to impaired blood flow (such as in the case of a blood clot) and 20 percent are due to bleeding (such as in the case of a leaking aneurysm).  Stroke is the second most common cause of both mortality and disability worldwide. In the United States, approximately 800,000 new strokes are reported every year.  Many stroke survivors need intensive rehabilitation to regain independence with their activities of daily living.  But what if these strokes were prevented before they ever occurred?  Many of the risk factors for stroke can be addressed with lifestyle changes and medical management.  In fact, there is evidence that modifiable risk factors may account for 90% of the risk of stroke.

Stroke Risk Factors

Lifestyle factors

Physical inactivity

Physical inactivity increases risk of stroke by 25-30%.  It also improves control of other risk factors for stroke, such as high blood pressure.  Adults are recommended to engage in 40 minutes of moderate to vigorous aerobic exercise 3-4 days per week.


Diets low in sodium and high in potassium have been shown to decrease the risk of stroke.  The DASH diet (Dietary Approaches to Stop Hypertension) is one such diet which emphasizes fruits and vegetables, low-fat dairy foods as well as moderate amounts of fish, poultry, whole grains, and nuts.  A Mediterranean style diet supplemented with nuts may also have some benefit.

Smoking, alcohol, and drugs

Individuals who smoke have a 2-4 times increased risk of stroke.  Counseling and medication therapy may be used to aide in quitting.  For those who consume alcohol, no more than 2 drinks per day for men and 1 drink per day for women is recommended.  Users of other drugs should be encouraged to take part in an appropriate treatment program.

Medical Risk factors


Blood pressure should be checked at regular doctor visits.  For those with blood pressure between 120-139/80-89, lifestyle modifications may be recommended.  If blood pressure is more than 140/90, medication may be used to lower blood pressure.  Maintaining a blood pressure at this goal can decrease stroke risk 32%.  Using a home blood pressure device may be helpful in monitoring blood pressures more closely.


High levels of total cholesterol and low levels of HDL cholesterol are associated with increased stroke risk.  Depending on the levels, lifestyle modification or medications may be recommended.  Statin medications have the most evidence for preventing stroke.


Studies have shown increasing body mass index also increases risk of stroke.  Higher waist to hip ratio, in particular, is associated with stroke risk.  Weight reduction in overweight and obese individuals is recommended.


Individuals with diabetes have a 2 to 6-fold increased risk of stroke.  While it is unclear that controlling blood sugar decreases stroke risk, tight blood pressure control and statin medications for diabetic patients have been shown to decrease risk of stroke.

Atrial fibrillation

In individuals with atrial fibrillation, the abnormal heart rhythm makes it more likely that clots may form in the heart, which may then break off and cause a stroke.  Depending on a variety of risk factors, the doctor may prescribe a blood thinner to decrease the risk of these clots and a subsequent stroke.


Other valvular heart diseases, plaques in the blood vessels leading to the brain, sickle cell disease, sleep apnea, migraines, hormone replacement, chronic inflammatory conditions, and conditions that increase the likelihood of the blood to clot may also increase the risk of stroke and should be closely managed by a physician.

If you have concerns about your stroke risk, it is important to communicate with your physician.  Working together, there are many strategies that can reduce your likelihood of a stroke.