The notion that better sleep makes a better marriage isn’t entirely new. A large body of research suggests that sleep-deprived people are more unpleasant and even hostile in their social interactions than those who get adequate sleep. People tend to use more negative words when they are sleep deprived than on days when they have had a full night’s sleep. A 2010 study found that men were more likely to fight with their wives after a night of disturbed sleep. In a 2014 study, couples who reported poor sleep during a two-week period reported more daily marital conflict than those who got better sleep.

But the Ohio State study went a step further to measure how marital discord combined with sleep deprivation can become toxic to a person’s health. Each partner in the study also gave blood samples, before and after the fight with their spouse. The samples were to measure markers of inflammation, which has been linked with heart disease, cancer and other health problems.

The study found that when married partners got less sleep, not only were they more likely to have hostile conflicts, but they also had higher levels of inflammatory proteins in their blood after those conflicts. In short, marital discord is more toxic to your body when you haven’t gotten enough sleep.

“Lack of sleep not only hurts the relationship,” said Dr. Kiecolt-Glaser, the senior author on the study, which was published in May in the journal Psychoneuroendocrinology. “It makes relationship conflict harder on the body.”

There was some good news from the study. When one partner got more rest, it was possible to mitigate the impact of sleep deprivation on the other partner. Couples with one rested partner were less likely to engage in hostile exchanges than when both partners were sleep deprived.

“Sleep and conflict worked together to increase inflammation, but both partners’ sleep mattered,” said Stephanie Wilson, the study’s lead author and a postdoctoral fellow at Ohio State. “When one person was rested, it protected the couple from being more nasty to each other.”

Sleep problems in a relationship aren’t uncommon. The National Sleep Foundation found that nearly 25 percent of couples sleep in separate beds. Other research shows that having a bed partner affects how much and how well a person sleeps. And when one relationship partner doesn’t sleep well, his or her partner is more likely to report poor health and well-being.