Local government leaders have called for loneliness to be recognised as a major public health issue following a report showing one in eight people have no close friends.
Relate said one in five people are lonely some of the time or all the time - a sharp rise on the previous year.
Increased dependence on social media, a lack of work/life balance and the pressures of bringing up children were among the possible reasons for the problem.
Cllr Izzi Seccombe, chairman of the Local Government Association’s Community Wellbeing Board, said research showed loneliness could be more harmful than smoking 15 cigarettes a day.
She said: 'We have long been calling for loneliness to be recognised as a major public health concern and we support Relate in drawing attention to this increasingly important issue.
'Loneliness and social isolation have a major impact on people’s health and wellbeing.
'We all need to wake up to this problem, which is placing an increasing burden on health and social care.'