In most cases, menopause is the natural result of aging. As women reach their 40s, their hormone production begins to decrease, and less estrogen and progesterone are available. That impacts fertility and can also lead to the unwanted side effects of menopause.
In other circumstances, menopause is induced prematurely. That’s often the result of a hysterectomy that includes the removal of both ovaries, leading to an immediate halt in the production of reproductive hormones. Specific chemotherapy and radiation treatments can also stop menstruation, although this may not be permanent.
A small percentage of women — about 1% — have naturally occurring premature menopause. Referred to as primary ovarian insufficiency, this occurs when your ovaries don’t produce enough estrogen and progesterone; it’s often the result of genetics or an autoimmune disorder.