Men who do not openly express their anger if they are unfairly treated at work double their risk of a heart attack, Swedish research suggests.
The researchers looked at 2,755 male employees in Stockholm who had not had a heart attack when the study began.
They were asked about how they coped with conflict at work, either with superiors or colleagues.
The researchers say their study shows a strong relationship between pent-up anger and heart disease.
Writing in the Journal of Epidemiology and Community Health, the researchers called the various strategies for keeping things bottled up, covert coping.