Well, a good one can. Recent studies show that married people are less likely to get pneumonia, have surgery, get cancer or have heart attacks, writes New York Times columnist Tara-Parker Pope. Marriage may even lower your risk for dementia.

But troubled relationships are another story. They can weaken your immune system and increase your risk of heart attack,  pneumonia and cancer.

How to avoid landing yourself in a “troubled relationship”? Fight fairly. For tips on that Herculean task and others, read our book.

Photo credit: Ajda Gregorčič at flickr