There’s nothing wrong with living alone, and there’s surely nothing wrong with enjoying solitude. Being lonely, however, is a whole different matter. Not only does it feel terrible, it can also harm your health. Here are five ways loneliness can be dangerous.
—Elevated cortisol: Loneliness can cause stress, which your body interprets as danger. In response, it releases the hormone cortisol, explains Julianne Holt-Lunstad, a professor of psychology and neuroscience at Brigham Young University. In occasional bursts, cortisol gins up your cardiovascular and immune systems, up-regulates your metabolism and more. That’s fine intermittently, but chronically elevated cortisol can dysregulate those same systems, contributing to heart disease, diabetes, cancer and more.
—Chronic inflammation: We tend think of inflammation as the overheated, reddened skin around a bite or a wound. That’s part of the inflammatory process, but so is a more systemic release of blood proteins that prep the immune system to deal with danger or injury. As with cortisol, loneliness-related stress can cause inflammation to become chronic, says Dr. Robert Waldinger, director of Harvard University’s Adult Development Survey. And as with elevated cortisol, that can lead to a host of diseases.
—Poor diet: Not everyone who spends a lot of time alone eats a pint of ice cream straight from the container and calls it dinner. But people who live together are likelier to cook together or go out to for meals together — and to put more thought into what they eat, too. Choosing and preparing your meals carefully is less likely when you’re alone and lonely — as many studies, including one in the International Journal of Eating Disorders, have shown — especially if you’re trying to medicate sadness or depression with food.
—Too much booze: There are few things that are better at preventing you from pouring yourself just one more than having someone around to ask you if you really need one more. It’s far too much to say that loneliness drives people to drink, but people are likelier to practice moderation in all things when they’re accountable to someone else. As with food, if loneliness leads to depression, excess drinking can be a quick but dangerous route to trying to feel better. This is especially so among people who are middle-aged and older, according to a 2016 study in the Journal of Aging and Health.
—Too little exercise: Life on the couch binge-watching TV can look awfully tempting when there’s little else to keep you engaged. But it’s a bad go-to when the loneliness is constant. Holt-Lunstad says that exercise is one of the most effective ways to address loneliness-related gloom. Even a brisk walk can make a significant difference — not least because it puts you in the company of other people.