The stress and anxiety brought on by a rocky marriage or relationship can take its toll on your heart, a study says.
Rowing with your partner may make you stressed and worried
Previous research has suggested that those in a relationship enjoy better health than singleton contemporaries.
But this latest study of 9,000 British civil servants suggests that picking an unsuitable partner may be worse for your heart than not picking one at all.
Negative relationships boost the risk of heart problems by 34%, the Archives of Internal Medicine study suggested.
The civil servants completed questionnaires about their close relationships in the 1980s.
They were then followed by researchers at University College London for 12 years. Of the 8,499 individuals who did not have heart problems to begin with, some 589 reported a heart condition subsequently.
Those who reported close relationships which featured arguments, criticism and other types of conflict were more likely to be in the group which registered the problems.
The association was weakened somewhat after the researchers adjusted for negative personality traits and depression, but still remained "significant", the authors said.
The authors explained their findings in reference to the "wear and tear" on organs that emotional fluctuations could cause, through for example hormonal changes and disturbances in blood clotting.
Cathy Ross, a cardiac nurse at the British Heart Foundation said the study "reinforces a well-known fact that lack of emotional and psychological support may increase the risk of heart disease".
"Identifying groups of individuals who are at risk and ensuring psychological support can make a big difference. It allows people to deal with their negative emotions."