About 1.3 million women in the United States enter menopause each year, amounting to a total of more than 55 million women currently in a perimenopausal or menopausal stage of their life. Given those numbers, about 20 percent of the American workforce consists of women adjusting to a new stage of life.
Menopause is a natural state brought on by hormonal changes that occur in a woman's midlife. At this point, the ovaries stop producing hormones such as progesterone and estrogen, and monthly periods cease. Usually, this process begins around the age of 50 but can happen as early as 45 or even much later, depending on each individual.
A woman taking hormonal suppressants or undergoing an oophorectomy (removal of the ovaries) will experience chemical or surgical menopause, respectively, which bring about the same symptoms.