Coronary artery disease (CAD) is the major cause of heart attacks. Therefore, the more risk factors you have for CAD, the greater your risk for developing unstable angina or having a heart attack. Smoking, diabetes, high cholesterol, high blood pressure, and a family history of heart disease are all strong risk factors for coronary artery disease. For more information, see the What Increases Your Risk section of the topic Coronary Artery Disease.

Use the heart attack risk calculator to estimate your risk of having a heart attack over 10 years. This tool is designed to estimate risk in adults age 20 and older who do not have heart disease or diabetes.

Even if you already have coronary artery disease or have had a heart attack, you can still lower your risk of another heart attack. To lower your risk:

• Stop smoking. Quitting smoking is probably the most important step to decrease your chance of a heart attack. Avoid secondhand smoke too.
• Reduce high cholesterol. High cholesterol can lead to a buildup of cholesterol inside your arteries.
• Lower high blood pressure. High blood pressure damages the coronary arteries and increases the heart's workload.
• Manage diabetes. People who have diabetes develop hardening and narrowing of the arteries more frequently and at a younger age than those not affected by diabetes. Keeping blood sugar at normal levels can slow this development.
• Stay at a healthy weight. Weight loss frequently improves blood pressure and cholesterol levels and may also help control diabetes.
• Be physically active. Regular exercise can help reduce your risk of heart attack by helping you to control cholesterol and blood pressure, regulate blood sugar (important for people with diabetes), and lose weight. Try to do activities that raise your heart rate. Exercise for at least 30 minutes on most, preferably all, days of the week.
• Manage depression and emotions. Treating depression and treating anger problems are important steps in improving cardiac and overall health and quality of life.
• Reduce stress. Stress causes increased blood pressure and heart rate and causes your arteries to narrow, increasing your risk for heart attack.
• Evaluate birth control pill and hormone replacement therapy use. Birth control pills are more likely to increase a woman's risk if she is older than 35 and smokes cigarettes. Hormone therapy (estrogen with or without progestin) may increase the risk for heart disease. This risk is higher for some women than others.
• Take an aspirin every day (check with your doctor first to make sure you have no medical reasons for not taking it).
• Avoid getting sick from the flu. Get a flu shot every year.
• Take all of your medicines correctly. Taking medicine can lower your risk of having another heart attack or dying from coronary artery disease.