According to a new study by US researchers, the people grieving over the loss of a loved one have increased risk of a heart attack.

Researchers studied 2,000 adults who survived a heart attack and noted that those who had lost a loved had 21 times higher risk of a heart attack than normal in the first day. The researchers said that the risk declined to six times higher than normal in the first week and gradually over the month.

Feeling grief causes symptoms like higher heart rate, blood pressure, stress hormone levels and blood clotting. Stress, lack of sleep and forgetting to take regular medication increase the risk of a heart attack in people.

The researchers at Harvard Medical School's Beth Israel Deaconess Medical Center and School of Public Health's epidemiology department in Boston, Massachusetts studied charts and patient interviews after a heart attack from 1989 to 1994.

Elizabeth Mostofsky, lead author of the research said, "Friends and family of bereaved people should provide close support to help prevent such incidents, especially near the beginning of the grieving process."

The findings have been published in Circulation: Journal of the American Heart Association.