Do you get so angry you clench your fists and raise your voice? Well, you need to calm down. Losing your temper could trigger a heart attack or stroke, according to research in this month's European Heart Journal. The research, by a team from Harvard Medical School, found that an angry outburst increased the risk of a heart attack in the following two hours by between 2.4 and 7.3 times. For a stroke, it was between 1.7 and 7.6 times. The risk increased the more often people got angry, or if they already had heart problems or diabetes.
The variability of the risk is because the research used pooled data from different studies, which took place in different countries and asked about different time periods. But Elizabeth Mostofsky, the lead author on the paper, says the evidence from the nine studies they analysed shows that the people affected had higher levels of anger before their heart problem or stroke compared to other times. So do you need to take anger management classes, or is it still safe to yell occasionally?
While the link between long-term stress and anxiety and heart attacks is well established, the short-term risk of an outburst is less so. This study, for example, could not find a clear link between how angry a person was and their risk of a heart attack and stroke (so there was no clear evidence of a stronger link if people hurled punches instead of insults, for example).
The mechanism by which anger could be damaging is, however, well understood. Anger is known to raise blood pressure, increase the heart rate and stiffen blood vessels. This disturbs the blood flow and promotes clot formation – with the potential to trigger a heart attack or stroke.
Acute stress has the same effect, suggesting that short bursts of strong negative emotions may be hurtful to hearts. A Swedish study of 1,381 men and women, published in the Journal of Epidemiology and Community Health, found that having a high-pressure deadline at work led to a six-fold increase in the risk of a heart attack within the next 24 hours.
The actual risk of a deadline or angry outburst giving you a heart attack is small. The studies looked at raised voices and fist-clenching, not losing control and hurling things, so you could try counting to 10, walking away from the situation or asking yourself if it really matters. Eating healthily, exercising and stopping smoking are all likely to be more important in reducing your risk of heart disease than controlling your temper – and exercise has the added benefit of reducing stress and anger.