It is also associated with poor mental health and, more surprisingly, with conditions such as cardiovascular disease, hypertension and dementia.

By Philippa Roxby Health reporter, BBC News

“No man is an island, entire of itself; every man is a piece of the continent, a part of the main,” wrote the poet John Donne in the 17th century, in an expression of loneliness and longing.

Some people seek isolation, but few choose to be lonely, primarily because it isn’t good for us.

Loneliness doesn’t just make people unhappy, research shows that it has an effect on mortality too.

It is also associated with poor mental health and, more surprisingly, with conditions such as cardiovascular disease, hypertension and dementia.

Loneliness is a public health issue that should be tackled urgently, says Laura Ferguson, director of the Campaign to End Loneliness, a coalition of organisations working to combat the problem including Age UK.