Loneliness can have a devastating impact on your health, with a lack of social connections putting you at risk of a number of serious conditions, an expert says.
Not only does severe loneliness cause emotional pain, it also leads to physiological changes that may not be immediately noticeable but can significantly impact long-term health.
The harmful effects of loneliness on health can be traced back to evolution, with one expert warning that it increases the risk of diabetes, heart disease and Alzheimer's disease .
Science writer David Robson has described friendships as "the ultimate cure" for many societal ills, just as exercise helps ward off many diseases and physical conditions.
Loneliness triggers a strong physical response because of our evolutionary history, where isolation often meant certain death. This is why loneliness increases blood clotting factors and inflammation in the body.
These physiological changes may not be immediately apparent, but they can cause significant damage if the loneliness they cause persists for a long time.
"Inflammation and blood clotting may be helpful in the short term if you have a wound, but in the long term it will increase your risk of Alzheimer's disease, stroke or heart attack," the expert added.
"Stroke and heart attack are the two things most closely linked to loneliness," he concluded. "The mechanism is completely tied to our evolutionary history."