What it likely boils down to is stress ? a well-known contributor to health problems, as well as a potential byproduct of troubled relationships, the scientists said.

In a study of 9,011 British civil servants, most of them married, those with the worst close relationships were 34 percent more likely to have heart attacks or other heart trouble during 12 years of follow-up than those with good relationships. That included partners, close relatives and friends.