As everyone – especially Taylor Swift – knows, nothing sells like heartache. The longing, the arguments, the melancholy; the feeling of heartbreak can leave us feeling like we are truly sick, maybe even mortally ill. 

But relationships can have an effect on your health, and the most influential ones are not romantic.

A new US study has claimed that blood relations, rather than romantic entanglements, have more bearing on our health and likelihood of developing chronic illnesses. 

A survey of more than 2,800 middle-aged people going back as far as 1995 found that people who had difficult family relationships developed between 0.5 and one more chronic illness when followed up 20 years later, compared to those who had happy and stable relationships with their family. 

Meanwhile, the researchers of the study – which was published in the Journal of Family Psychology – did not find any significant proof that romantic relationships affect you in the same way. 

"We were honestly stunned that there were zero associations between intimate partner emotional climate and later health," said lead author Dr. Sarah Woods, assistant professor of family and community medicine at the University of Texas Southwestern Medical Centre, as quoted in the Telegraph

"Most often, researchers focus on romantic relationships, especially marriage, presuming they likely have more of a powerful effect on health. 

"We found that family emotional climate had a big effect on overall health, including the development or worsening of chronic conditions such as stroke and headaches over the 20-year span of midlife."

The survey focused on how family dynamics and tension can affect a person's health, and questions included 'how often do members of your family criticise you?' and 'how much can you rely on your family for help if you have a serious problem?' 

Data would be collected on the participants at three separate times, and each time their total number of chronic conditions – such as headaches, stroke and stomach trouble – over the previous 12 months would be measured to gauge their health. 

Dr. Woods shed some light on the impact of these chronic illnesses, saying that the cost that comes with them means the family strain is costly, both financially and physically. 

"For adults who already have a chronic condition, a negative family emotional climate may increase their poor health and conversely, supportive family members may help improve their health outcomes," added Dr. Woods.

"This is why I encourage patients to bring supportive family members with them to their doctors' visits and to create an open dialogue about their health conditions and concerns. Having that support definitely has a significant effect on the quality of life and well-being."