An unhappy marriage can triple the chances of a man going to an early grave, a landmark study into the health hazards of unhappy private lives has found.

Women reported much the same stresses from a demanding spouse but it was less likely to kill them.

The Danish study tracked the work and health patterns of 10,000 men and women aged between 36 and 52 over 10 years.

It found endless fighting with a spouse can in fact be the death of you, especially if you are out of work - and riskier still if you are a man.

The study found 6 per cent of men and 4 per cent of women went to an early grave.

The main cause of death was cancer, followed by heart disease, stroke, liver disease, and suicide.

But the researchers say at least half of the deaths could have been prevented if the person had not also been suffering from the added burden of a hostile marriage, a difficult relationship with their children, and often no way to escape them after a job loss.

"Of course not all arguments will end up having this deadly end, but in general if you have these stressful relations, very frequently that will lead to an increased risk of death," study author Professor Rikke Lund said.

The research contradicts other studies that find married men fare better, live longer and are healthier.

Professor Lund says that may be true generally, but it depends on the relationship.

Unemployment was also found to be a factor.

"What we were able to identify were that people outside the labour force seem to be more vulnerable to these kind of stressful relations, as were men who had these worries and demands from their partners," Professor Lund said.

"So we sort of identified some especially vulnerable groups among the unemployed and some men."