The protective effect of oestrogen
Oestrogen is a hormone made by the female body (mainly by the ovaries) that enables women to have children and helps keep their bones healthy. The oestrogen level is highest during childbearing years and declines with menopause.

It is thought that oestrogen plays a protective role in the development of heart disease in women, but as oestrogen levels gradually decrease after menopause the protection against heart disease reduces. Menopause increases the risk of heart disease in women by 3 times. After age 60 men and women are at equal risk of developing heart disease.

A hysterectomy (removal of the uterus and ovaries) increases the risk of heart attack sharply (if not on hormone replacement therapy) but if menopause occurs naturally, the risk increases more slowly.