Although your mother or grandmother may have used "the change" to refer to menopause, it isn't a single event. Instead, it's a transition that can start in your 30s or 40s and last into your 50s or even 60s. You may begin to experience signs and symptoms of menopause well before your periods stop permanently. Once you haven't had a period for 12 consecutive months, you've reached menopause.
Menopause is a natural biological process, not a medical illness. Although it's associated with hormonal, physical and psychosocial changes in your life, menopause isn't the end of your youth or of your sexuality. Several generations ago, few women lived beyond menopause. Today, you may spend as much as half of your life after menopause.
Menopause is defined as absence of menstrual periods for 12 months. The menopausal transition starts with varying menstrual cycle length and ends with the final menstrual period. Perimenopause means "around the time of menopause." It is not officially a medical term, but is sometimes used to explain certain aspects of the menopause transition in lay terms. Postmenopause is the entire period of time that comes after the last menstrual period.
Menopause is the time in a woman's life when the function of the ovaries ceases. The ovary, or female gonad, is one of a pair of reproductive glands in women. They are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. The ovaries produce eggs (ova) and female hormones such as estrogen. During each monthly menstrual cycle, an egg is released from one ovary. The egg travels from the ovary through a Fallopian tube to the uterus.
The ovaries are the main source of female hormones, which control the development of female body characteristics such as the breasts, body shape, and body hair. The hormones also regulate the menstrual cycle and pregnancy. Estrogens also protect the bone. Therefore, a woman can develop osteoporosis (thinning of bone) later in life when her ovaries do not produce adequate estrogen.
Perimenopause is different for each woman. Scientists are still trying to identify all the factors that initiate and influence this transition period.
Menopause begins naturally when your ovaries start making less estrogen and progesterone. During your reproductive years, these hormones regulate your monthly cycles of ovulation and menstruation. In your late 30s, the amount of progesterone your body produces diminishes, and the remaining eggs from your ovaries are less likely to be fertilized. Eventually your menstrual periods stop, and you can no longer become pregnant. Because this process takes place over years, menopause is commonly divided into the following two stages:
Perimenopause. This is the time you begin experiencing menopausal signs and symptoms, even though you're still ovulating. Your hormone levels rise and fall unevenly, and you may have hot flashes and variations in your periods. For instance, your flow may be irregular or heavier or lighter than usual. This is a normal process leading up to menopause and may last four to five years or longer.
Postmenopause. Once 12 months have passed since your last period, you've reached menopause. Your ovaries produce much less estrogen and progesterone, and they don't release eggs. The years that follow are called postmenopause.