They say never go to bed angry—but what about waking up angry? If you’ve ever spent an entire night tossing and turning, and then immediately started your day by snapping at your significant other, you’re not alone. And science says it’s not really your fault.

A new study published in the journal Psychoneuroendocrinology says that missing out on quality shut-eye doesn’t just make you cranky and irritable—it also puts you and your loved ones at risk for stress-related inflammation, which is associated with a higher risk of cardiovascular disease, diabetes, arthritis, and other diseases. So lack of sleep (plus the inevitable fight when your partner forgets to take out the trash again) equals an increased chance of inflammatory-related diseases for everyone involved.

“If these problems persist over time, you can get this nasty reverberation within the couple.”

While it’s long been known that sleep problems can be linked to inflammation and some chronic illnesses, the research team at The Ohio State University Institute for Behavioral Medicine Research wanted to find out whether one partner’s lack of sleep could affect the other. So they rounded up 43 couples and tested their sleep, blood samples, and conflict-resolution abilities.

The verdict: While people who slept less didn’t necessarily wake up with higher inflammation, they did have greater inflammatory responses to conflicts when they arose. “So that tells us less sleep increased vulnerability to a stressor,” says Stephanie Wilson, lead researcher on the study.

When both partners got fewer than seven hours of sleep for two nights in a row, the couple was more likely to argue. For every hour of sleep lost, the levels of two inflammatory markers in the body rose 6 percent. (And shout out to the extra-angry couples, whose “unhealthy tactics” during a fight led to a 10 percent increase with each hour of less sleep.)

“Part of the issue in a marriage is that sleep patterns often track together. If one person is restless, or has chronic problems, that can impact the other’s sleep. If these problems persist over time, you can get this nasty reverberation within the couple,” said Janice Kiecolt-Glaser, the study’s senior author and director of the Institute for Behavioral Medicine Research. “It’s important to find good ways to process the relationship and resolve conflict—and get some sleep.”

According to the Centers for Disease Control and Prevention, 35 percent of Americans get less than the recommended seven hours of sleep per night. So the next time your S.O. wants to stay up late watching Netflix, convince him or her to power down and hit the lights. It just may save your relationship (and improve your health) in the morning.

Falling—and staying—asleep isn’t always easy, though. Try these 5 habits of one highly successful sleeper the next time you can’t stop tossing and turning. And Salma Hayek says it’s no accident that she sleeps like a baby—here’s her secret.