What does it mean to die of a broken heart?
Its means literally that; your heart is broken by extreme sadness, and you die.It used to be thought that the person was simply too sad to function properly and they really did not die of a broken heart. However, more recent science has shown there are physiological changes that come with a "broken heart" than can cause physical death.
When a person endures sudden shock or extreme stress, the adrenal glands release adrenaline. That provides an extra boost of energy and chemicals that temporarily mask physical pain. This enables the "fight or flight" reflex so a person under attack will be essentially turbo-charged for a short period of time. Usually, releases of adrenaline are short-term; the threat passes, and the person calms down and things return to normal.
The problem is that grief, such as that caused by the loss of a loved one, can result in a prolonged release of adrenaline, which causes damage to the heart. Many doctors and scientists now think that this prolonged release of adrenaline and the damage to the heart is causes can lead to heart failure, especially in older persons, who are then said to have "died of a broken heart."