Traditional wedding vows often include the promise to be by your spouse’s side "in sickness and in health, 'til death do you part." Or something similar. Well, if you are in a bad marriage, the death part may come sooner than expected.

A new study finds that a stressful marriage may be unhealthy, especially for men. In fact, for some people it may be as bad as smoking.

This finding seems to be opposite of many other studies that say marriage improves health. For example, one British study found that being married improved a person’s chances of surviving a heart attack. The researchers said married people had shorter hospital stays.

And experts at Harvard Medical School write on their website that married people:
live longer
have fewer strokes and heart attacks
have a lower chance of becoming depressed

are less likely to have advanced cancer at the time of diagnosis and more likely to survive cancer for a longer period of time
and survive a major operation more often.

One way to make sense of conflicting findings about marriage is to consider the quality of the relationship. Do the partners support each other, or do they give each other long-term, chronic stress?

To find out how bad a stressful marriage is on health, researchers at two universities in the United States -- the University of Nevada, Reno and the University of Michigan -- teamed up. They followed 373 couples for 16 years.

The researchers wanted to know if often conflicting over certain topics affected a person's health in a negative way. These topics included such things as children, money, in-laws and recreational activities.

They found a conflict-filled relationship harms the body in many ways. People in a stressful relationship can have damaging inflammation, extreme changes in appetite and increased levels of stress hormones. All these conditions can negatively affect many systems -- from heart function to how the body is able to fight diseases.

The researchers also found that a bad marriage was harder on men’s health than on women’s.

A good marriage is not without arguments, stress and disagreements. What seems to matter most is how a couple speaks to each other. How do they handle their differences? How do they resolve an argument?

One of the lead researchers is Rosie Shrout with the University of Nevada, Reno. In an interview with The Guardian, Shrout says, “Conflict can be particularly damaging for health if spouses are hostile or defensive during disagreements." She adds that arguing about the same topic over and over again without finding a solution can also damage a person’s health.

Shrout also spoke with The Guardian about the health benefits of marriage. She said the act of getting married does not make people healthier. Instead, she said, the support married people give each other can help them stay healthier, heal faster, and have better mental well-being.

On the website Women’s Health, relationship experts and happy couples give their tips on how to keep a relationship healthy. Here are a few.

Stop keeping score. A healthy relationship is not about winning and losing. In the bigger picture, who made the most money or who emptied the dishwasher last is not important.

Touch more. It does not have to be sexual touching. Simply holding hands can create stronger feelings between people. But now that we’re on the subject, relationship experts claim that having more sex does help a couple stay close.

Accept your in-laws. No family is perfect. Experts warn against complaining about your partner’s family or trying to change them. Having a sense of humor is often the best approach.

Turn off social media, stop texting, hide your phone and just hang out. Turning off social media and technology gives a couple the space to just be themselves. Playing a game, cooking a meal or taking a walk allows a couple to have simple fun together.

Learn how to fight fairly. Even couples in healthy relationships disagree. A relationship expert suggests that understanding how the other person deals with conflict can help a marriage in a big way. And don’t be afraid of losing a fight. Remember the earlier tip about not keeping score.