Bereavement, relationship breakdown and mental health issues can all lead to loneliness that many find hard to cope with and even talk about.
The Campaign to End Loneliness suggests more than a million people in the UK are affected and it isn't just a problem for the elderly, with many young and middle-aged sufferers too.
Victoria Derbyshire presenter Joanna Gosling spoke to a panel of guests about loneliness ahead of a BBC One programme to be broadcast on Thursday night.
Sue Bourne, the film-maker, talked about the project alongside Richard Smith, Kylie Taylor and Emily Jones who feature in the documentary.
