Medical researchers increasingly are finding just how toxic outbursts of anger can be.

New evidence suggests people increase their risk for a heart attack more than eightfold shortly after an intensely angry episode. Anger can also help bring on strokes and irregular heartbeat, other research shows. And it may lead to sleep problems, excess eating and insulin resistance, which can help cause diabetes.

“Anger is bad for just about everything we have going on physically,” says Redford Williams, director of the Behavioral Medicine Research Center at Duke University Medical Center and co-author of “Anger Kills: Seventeen Strategies for Controlling the Hostility That Can Harm Your Health.”

Strong anger releases the hormones adrenaline and cortisol into the bloodstream, which can trigger an increase in heart rate, blood pressure and sugar metabolism. This is useful if the body requires a burst of energy to mount a physical attack. “Amongst cave men, the more angry you got, the more aggressive you were, the more food you got,” says Scott Wetzler, vice chairman of the department of psychiatry at Montefiore Medical Center in New York.

But too much anger can be harmful, especially for people already at risk for heart disease, the leading cause of death in the U.S. About half of American adults have at least one of three key risk factors for heart disease: high blood pressure, high LDL cholesterol or a smoking habit.

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