We have all been alone, felt alone, or both at some point in our lives. A lifestyle change such as moving to a new location or starting a new job can produce feelings of solitude and impact our health in several ways. In the BrainCraft video, “Why Do We Feel Lonely?,” host Vanessa Hill explains the differences between being alone and being lonely, and the effects social isolation can have on our mind, body, and longevity.

There are people who feel lonely who are alone and there are those who choose to be alone who are not necessarily alone. A 2007 study published in the journal Genome Biology found loneliness could be in our genes. The team of researchers discovered a distinct pattern of gene expression in immune cells in participants who suffered from chronic loneliness. These feelings of solitude were associated with changes in gene expression that drive inflammation — known as one of the first responses of the immune system. Loneliness, especially for these participants, causes a yearning for social connection in the same fashion hunger makes us crave food.

“There's a thing about being alone and there's a thing about being lonely, and they're two different things. I was alone, but I was not lonely. On the backside of the moon, I didn't even have to talk to Houston and that was the best part of the flight,” said Al Worden, the Apollo 15 pilot who was about 2240 miles away from his colleagues. Worden spent three days alone in orbit miles away from his home and out of contact with those on Earth.

While solitude can stimulate creativity and even improve our attention span, it can also have deadly consequences. A 2013 study published in the journal Psychological Science found social isolation increased people’s likelihood of death by 26 percent, even when people didn’t consider themselves lonely. Social isolation and living alone were found to be even more devastating to a person’s health than feeling lonely.

The human species is inevitably a social species that has depended on other members since birth. We’re social creatures that need other people in order to be well and thrive. Naturally, surrounding ourselves with others and fostering close relationships are the antidote to living happy, healthy, and well.