Most women think of menopause as the time of life when their menstrual periods end. This usually occurs during middle age, when women are also experiencing other hormonal and physical changes. For this reason, menopause is sometimes called the "change of life."
A woman is said to be in menopause after she has gone for one full year without periods. While most women in the United States go through menopause around the age of 51, a small number will experience menopause as early as age 40 or as late as their late 50s. Rarely, menopause occurs after age 60. When menopause is diagnosed before age 40, it is considered to be abnormal or premature menopause.
In women, the ovaries produce the female hormones estrogen and progesterone. Estrogen and progesterone control a woman's periods and other processes in her body. As a woman approaches menopause, her ovaries gradually makes less and less of these hormones.
As hormone levels fall, a woman's pattern of menstrual bleeding usually becomes irregular. Many women experience light, skipped or late periods for several months to a year before their periods stop altogether. Some women may experience heavier-than-normal bleeding. Heavier-than-normal bleeding should be evaluated by a doctor to exclude problems in the genital tract.
It is important to realize that until menopause is complete, a woman still can become pregnant even when periods are light or missed.
For most women, menopause is a normal process of aging. If a woman has had her ovaries removed by surgery or has had damage to her ovaries for other reasons, such as radiation therapy, she may become menopausal from that process.
Perimenopause, also known as the climacteric, includes the time before menopause when hormonal and biological changes and physical symptoms begin to occur. This period lasts for an average of three to five years.