As a woman ages, the levels of estrogen and progesterone produced by the ovaries start to decline. When the supply of eggs is finally exhausted, ovulation stops. The levels of estrogen and progesterone eventually drop so low that menstruation stops. A woman knows she has passed menopause when she has no periods for 12 months.
The lack of estrogen can bring on symptoms such as hot flashes and vaginal dryness. It can also increase the risk of osteoporosis (bone loss). Because of this, women may choose to take hormone replacement therapy to restore estrogen after menopause.

Before making a decision about HRT, talk to your doctor about what may work best for you, considering your personal needs and family and medical history.