The research: After looking at thousands of health records to see what effect anger had on health, Harvard School of Public Health researchers found that within 2 hours of an angry outburst, a person’s risk of heart attack increased nearly five-fold, their risk for stroke rose nearly four-fold, and their risk for heart arrhythmia also increased. The risks were highest in people who got angry more often and had existing risk factors such as prior heart problems or high blood pressure.  What it means: Getting angry changes our physiology, says Murray Mittleman, MD, director of cardiovascular epidemiology at Harvard. It increases heart rate and breathing and constricts blood vessels, increasing blood pressure. It also makes blood clot more readily. The bottom line: If you’re prone to outbursts, take lifestyle measures to reduce your risk for cardiovascular disease overall, Dr. Mittleman says. Keep your cholesterol in line, don’t smoke, and exercise regularly. That way if you do lose your cool, it’ll be less likely to cause a serious problem. Research suggests that a regular practice of cultivating calmness can cut cardiovascular disease, says Stephen Devries, MD, executive director of the Gaples Institute for Integrative Cardiology. One study found that people who meditated for 20 minutes, twice a day, halved their risk for heart problems. Another found that people who did 45 minutes of yoga, twice a week, reduced their risk for dangerous heart arrthymnia. “No matter what your predisposition, you can learn to turn down your emotional thermostat, so your are less likely to boil over when a stressful situation arises,” Dr. Devries says. When you do get angry (it happens to the best of us!), don’t smolder. Take a walk, talk with a friend, take a few deep breaths, and let it go. MORE: 15 Surprising Ways to Improve Your Cholesterol