It is possible to die from a broken heart, mounting evidence shows.
The risk is highest in the early weeks following loss
A review of recent work, published in The Lancet, found that the risk of death increases by up to a fifth following bereavement.
Investigator Margaret Stroebe of Utrecht University, The Netherlands, said the psychological distress caused by the loss played a big part.
Heart experts say people who lose a partner often adopted unhealthy habits such as smoking and poor diet.
Indeed, for widowers, the increased death risk will probably be linked with alcohol consumption and the loss of their sole confidante, who would have overseen her husband's health status, the researchers told The Lancet.
In widows, the picture is not as clear, but intense loneliness and the psychological distress caused by the loss could play a large part.
Experts know psychological stress can cause physical changes in the body - stress hormones can disrupt body processes.
One study found men were 21% more likely to die after the loss of their wife. Widows had a 17% increased risk of death.
The risk appears to be highest in the early weeks following bereavement and decreased with time.
Men who lose a wife are also three times more likely to take their own life. Widows, however, do not have an increased suicide risk.
And Danish study from 2003 showed fathers and mothers have a raised suicide risk after the death of a child, a risk which is higher the younger the child and is particularly high in the first 30 days post-bereavement.
Dr Stroebe's team said: "The patterns are quite consistent, enabling the conclusion that the mortality of bereavement is attributable in large part to a so-called broken heart, the psychological distress due to the loss."
But they stressed that most people cope with grief without professional help.
Most reactions are not complicated and for most bereaved people, family and friends, religious and community groups, and various societal resources will provide the necessary support, the researchers said.
Rev Dr Peter Hammersley of Cruse Bereavement Care said: "This phenomenon has been recognised for some time. Loss of a close significant person such as a partner is a severe experience for the bereaved person who is left.
"On the positive side, there is good evidence indicating that the availability of personal support networks are a significant element in helping people who have been bereaved.
"Not everyone is fortunate enough to have a supportive family around. This is where bereavement support networks, such as Cruse Bereavement Care, can help."