Loneliness can cause an early death.
Some people can't stand to be alone and being alone too long after being around other people can basically cause the persons body to give up and die.
The loneliness itself is not the cause of death directly but when someone has other health issues or is getting up to older age then they may simply give up out of being lonely.
Some people who are in nursing homes die soon after being admitted to a nursing home as they are lonely when someone does not visit them and so they simply give up.
Even spouses can die soon after their spouse such as husband or wife dies and then leaves them alone.
A well-known review of research found that loneliness (the feeling of being lonely), social isolation and living alone were risk factors for early mortality, with an increased likelihood of death ranging from 26% to 32%.
Recent studies found that: Social isolation significantly increased a person's risk of premature death from all causes, a risk that may rival those of smoking, obesity, and physical inactivity.
Social isolation was associated with about a 50% percent increased risk of dementia.
Loneliness can be deadly: this according to former Surgeon General Vivek Murthy, among others, who has stressed the significant health threat.
Loneliness has been estimated to shorten a person's life by 15 years, equivalent in impact to being obese or smoking 15 cigarettes per day.