Menopause is the permanent end of menstrual periods and thus of fertility.
For up to several years before and just after menopause, estrogen levels fluctuate widely, periods become irregular, and symptoms (such as hot flashes) may occur.
After menopause, bone density decreases.
Menopause is usually obvious, but blood tests may be done to confirm it.
Certain measures, including drugs, can lessen symptoms.
During the reproductive years, menstrual periods usually occur in approximately monthly cycles, with an egg released from the ovary (ovulation) about 2 weeks after the first day of a period. For this cycle to occur regularly, the ovaries must produce enough of the hormones estrogen and progesterone (see Menstrual Cycle).
Menopause occurs because as women age, the ovaries run out of usable eggs and stop producing estrogen and progesterone. During the years before menopause, production of estrogen and progesterone begins to decrease, and menstrual periods and ovulation occur less often. Eventually, menstrual periods and ovulation end permanently, and pregnancy can no longer occur naturally. A woman’s last period can be identified only later, after she has had no periods for at least 1 year. (Women who do not wish to become pregnant should use birth control until 1 year has passed since their last menstrual period.)
Perimenopause refers to the several years before and the 1 year after the last menstrual period. How many years of perimenopause precede the last menstrual period varies greatly. During perimenopause, estrogen and progesterone levels fluctuate widely. These fluctuations are thought to cause the menopausal symptoms experienced by many women in their 40s.
The menopausal transition is the part of perimenopause that leads up to the last menses. It is characterized by changes in the pattern of menstrual periods.
In the United States, the average age for menopause is about 52. However, menopause may occur normally in women as young as 40. Menopause may start before age 52 in women who
Menopause is considered premature when it occurs before age 40. Premature menopause is also called premature ovarian failure or primary ovarian insufficiency.