Should I take an aspirin to prevent a stroke or heart attack? This is a great question and one that I frequently encounter in my practice.  Over 795,000 people have strokes every year and 130,000 will die from a stroke.  Aspirin is a very effective therapy because it impairs the formation of blood in the heart and brain that cause strokes and heart attacks.  Taking 75-81 mg of aspirin every day has been shown to reduce the risk of stroke by 17-28% (depending on the study).  With such great risk reduction at so little out-of-the pocket cost, why don’t doctors recommend that every adult take a daily aspirin for prevention?  Because the side effects of aspirin, namely gastrointestinal bleeding and ulcer formation, can be severe. In order to decide if aspirin is a safe and an effective treatment, you need to determine your risk of having a heart attack or stroke. If you have already had a stroke or heart attack, then you remain at high risk for a second occurrence and aspirin is likely a beneficial therapy.  If you have never had a stroke or heart attack, make an appointment with your physician to discuss your risk profile.  Patients at intermediate or high risk of a stroke or heart attack will likely benefit from taking a daily aspirin.  This is a helpful website, http://cvdrisk.nhlbi.nih.gov/calculator.asp to determine your risk; though please consult with a physician before deciding to start taking a daily aspirin.