But for other people, loneliness is a way of life, one that may stem not from the number of people around them but from a lack of connection with others. And, research has showed, chronic loneliness can have adverse consequences for your health
Scientists are still examining the link between mental and physical health and how loneliness affects our bodies. But you may not know about some of their findings over the years.
As CNN's Dr. Sanjay Gupta writes in a column for O Magazine
regarding a 2003 study
"A remarkable study led by Naomi Eisenberger, an associate professor of social psychology at UCLA, found that being excluded -- which can push you to the social perimeter and, as a result, cause feelings of loneliness -- triggered activity in some of the same regions of the brain that register physical pain.
"From an evolutionary perspective, this makes sense; our prehistoric ancestors relied on social groups not just for companionship, but for survival. Staying close to the tribe brought access to shelter, food, and protection. Separation from the group, on the other hand, meant danger.
"Today when we feel left out, our bodies may sense a threat to survival, and some of the same pain signals that would engage if we were in real physical danger are flipped on. In the chronically lonely, levels of the stress hormone cortisol shoot up higher in the morning than in more socially connected people and never fully subside at night."
It can keep you from getting a good night's sleep
People who feel lonely tend to experience more nighttime sleep disruptions than those who don't, a small 2011 study
Researchers found that the link between sleep disruptions and loneliness persisted even after marital status and family size were taken into account, suggesting that loneliness depends on how people perceive their social situation rather than the situation itself.
The 95 participants in the study all had strong social connections and were part of a close-knit, rural South Dakota community. Yet, researchers found, even small differences in their degrees of loneliness were reflected in their sleep.
It can increase your risk for dementia
In a 2012 study of nearly 2,200 older adults
living in Amsterdam, researchers found that participants who reported feeling lonely -- regardless of the number of friends and family surrounding them -- were more like