• People in an unhappy marriage are also at higher risk of depression
  • The stress of a bad marriage can raise blood pressure and heart rate
  • This can eventually lead to heart disease

Everyone knows that being in an unhappy marriage can make people miserable.

But now, researchers have suggests it could even prove fatal.

U.S. researchers believe that an unhappy marriage can cause stress which, in turn, affects physical health.

They believe people who are unhappy with their spouse could be at higher risk of depression, high blood pressure and even heart disease.

As a result, the scientists at Michigan State University are set to study how marriage affects cardiovascular health.

They say this is particularly important at a time when one in four people in the U.S. die of heart disease.

Dr Hui Liu, the lead researcher, said: ‘The importance of this study is highlighted by the continued high prevalence of cardiovascular disease in the United States.

‘We plan to provide nationally representative evidence on how marriage affects cardiovascular health and elucidate the multiple mechanisms in this relationship. The findings will have important implications for health policy and practice.’

The researchers say most cases of heart disease are preventable meaning identifying risk factors is crucial to the design of effective prevention strategies.

Experts say the stress of an unhappy marriage can lead to higher levels of the body's stress hormones. These increase blood pressure and heart rate which, eventually, causes heart disease

Dr Liu explained that scientists have long believed marriage to be the most important social relationship affecting health.

She believes, for example, that a happy marriage offers support and enhances physical health

In contrast, she says the stress of an unhappy marriage can cause depression.

This, she says, can promote unhealthy habits, such as smoking and drinking, and can increase the body’s levels of stress hormones.

These hormones can result in raised blood pressure and heart rate eventually leading to heart disease.

Dr Liu’s theory is supported by previous research which has shown that the happiness of marriage has a powerful influence on physical health.

Recent research from the University of Utah revealed that people who think their partner is not supportive are more likely to develop heart disease.

Scientists found that people who say their spouse is sometimes supportive but also sometimes upsetting have higher levels of artery calcification.

This suggests their arteries are diseased and they are at greater risk of premature death.

Another recent study, from UCLA, revealed that marriage is also good for a man’s bones.

It showed that men in stable marriages have stronger bones than those who are single or divorced.

The researchers are not clear as to the reasons behind this finding.