Menopause Quick Overview
- Menopause is the time when a woman stops having menstrual periods.
- Many women experience a variety of symptoms as a result of the hormonal changes associated with the transition to menopause. Around the time of menopause, women often lose bone density and their blood cholesterol levels may worsen, increasing their risk of heart disease.
- The average age of U.S. women at the time of menopause is 51 years. The most common age range at which women experience menopause is 48-55 years.
- Premature menopause is defines as menopause occurring in a woman younger than 40 years. About 1% of women experience premature menopause.
- Menopause is more likely to occur at a slightly earlier age in women who smoke, have never been pregnant, or live at high altitudes.
- The hormonal changes associated with menopause actually begin prior to the last menstrual period, during a three to five year period sometimes referred to as the perimenopause. During this transition, women may begin to experience menopausal symptoms even though they are still menstruating.
- Surgical menopause is menopause induced by the removal of the ovaries. Women who have had surgical menopause often have a sudden and severe onset of the symptoms of menopause.
What is menopause?
Menopause refers to the time at which a woman stops having menstrual periods. It is defined as the absence of menses for 12 consecutive months. The average age of menopause is 51 years, although this can vary widely.
What causes menopause?
Menopause occurs due to a complex series of hormonal changes. Associated with the menopause is a decline in the number of functioning eggs within the ovaries. At the time of birth, most females have about 1 to 3 million eggs, which are gradually lost throughout a woman's life. By the time of a girl's first menstrual period, she has an average of about 400,000 eggs. By the time of menopause, a woman may have fewer than 10,000 eggs. A small percentage of these eggs are lost through normal ovulation (the monthly cycle). Most eggs die off through a process called atresia (the degeneration and subsequent resorption of immature ovarian follicles - fluid filled cysts that contain the eggs).
- Normally, FSH, or follicle-stimulating hormone (a reproductive hormone), is the substance responsible for the growth of ovarian follicles (eggs) during the first half of a woman's menstrual cycle. As menopause approaches, the remaining eggs become more resistant to FSH, and the ovaries dramatically reduce their production of estrogen.
- Estrogen affects many parts of the body, including the blood vessels, heart, bone, breasts, uterus, urinary system, skin, and brain. Loss of estrogen is believed to be the cause of many of the symptoms associated with menopause. At the time of menopause, the ovaries also decrease their production of testosterone-a hormone involved in libido, or sexual drive.
How long does menopause last?
Menopause is reached at the point in time at which a woman has not has a menstrual period for 12 consecutive months. Therefore women have either reached this point (are post-menopausal) or have not (pre-menopausal). Menopause itself is not a process but denotes the time point when menses have ceased for 12 months in a row. However, the process of declining hormone levels prior to menopause has been referred to as perimenopause or the menopausal transition. This process can last for up to 10 years or more in some women and is variable in length.
Medically Reviewed by a Doctor on 1/8/2016
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