According to specialists, the death of a loved one makes people up to 21 times more likely to suffer a heart attack within a day of the loss.

Cardiologists also say that during the first week of bereavement, the risk is almost 6 times higher than normal.

The risk slowly declines during the month that follows, a study found.

Doctors are warning people of the dangers, especially for those closest to the person who died and who are already at risk of having a heart attack.

A U.S. study of almost 2,000 heart attack survivors found the increased risk of heart attack within the first week after the loss of a significant person ranged from one per 320 people at high risk to one per 1,394 people with a low heart attack risk.

The study is the first to look specifically at heart attack risk in the first days and weeks after bereavement.

Previous research shows grieving spouses have higher long-term risks of dying, with heart disease and stroke accounting for more than half of deaths – leading to the phenomenon known as “broken heart syndrome”.

According to experts, the stress caused by bereavement has immediate health effects, while loss of sleep and appetite can depress the immune system of surviving loved ones, which may aggravate existing underlying medical conditions.

The emotional strain also causes some bereaved partners to take their own lives, while others neglect their health and diet because of the pain of their loss.

Dr. Murray Mittleman, a preventive cardiologist and epidemiologist at Harvard Medical School’s Beth Israel Deaconess Medical Center and School of Public Health’s epidemiology department, in Boston, said: “Caretakers, healthcare providers, and the bereaved themselves need to recognize they are in a period of heightened risk in the days and weeks after hearing of someone close dying.”

Researchers reviewed health charts and interviewed 1,985 patients while in hospital after a confirmed heart attack between 1989 and 1994.

Patients answered questions about circumstances surrounding their heart attack, as well as whether they recently lost someone significant in their lives over the past year, when the death happened and the importance of their relationship.

The researchers estimated the relative risk of a heart attack by comparing the number of patients who had someone close to them die in the week before their heart attack to the number of deaths of significant people in their lives from one to six months before their heart attack.

Experts found after a significant person’s death, heart attack risks rose to 21 times higher than normal during the first day.

The risk was almost 6 times higher than normal in the first week, and declined steadily during the first months, says a report in the Journal of the American Heart Association.

The study shows bereaved people at high risk of a heart attack before the loss occurred were 4 times more likely to succumb themselves than those previously at low risk.

Psychological stress caused by intense grief can increase heart rate, blood pressure and blood clotting, which in the short-term can raise the chances of a heart attack.

Lead researcher Elizabeth Mostofsky said grieving people may neglect their own wellbeing, forgetting to take medication for heart and other medical problems.

“Friends and family of bereaved people should provide close support to help prevent such incidents, especially near the beginning of the grieving process.

“During situations of extreme grief and psychological distress, you still need to take care of yourself and seek medical attention for symptoms associated with a heart attack,” she said.

Heart attack signs include chest discomfort, upper body or stomach pain, shortness of breath, breaking into a cold sweat, nausea or lightheadedness.