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.