Overview of Menopause

Menopause is a normal time of transition brought on by lower levels of estrogen that continue into the postmenopausal phase. Find out more.

Menopause is a time of transition for a woman’s body. It signals the end of the menstrual cycle. It is perfectly normal. Most women make the transition without any medical help at all.

What is menopause?

Menopause means that a woman has had a final menstrual period without another occurring in the following year. A woman enters menopause when a year has passed since her last period. 

The few years before a woman’s final period is a time known as perimenopause. In this time, a woman’s ovaries produce less and less estrogen and progesterone. Those are the two major female hormones. They are in large part responsible for ovulation, menstruation, and pregnancy. Periods may become irregular or unusually light or heavy. Ovulation (the monthly release of an egg) declines and stops. Until menopause has occurred, a woman should still practice birth control if she wants to avoid pregnancy.

During the perimenopause, menstrual periods may become irregular or unusually light or heavy. Ovulation (the monthly release of an egg) declines and stops. Until menopause has actually occurred (that is, a year has passed since the last period), a sexually active woman should still practice birth control if she wants to avoid pregnancy.

Menopause also can be brought on by surgical removal of the ovaries. This is a procedure called an oophorectomy. It can also be caused by chemotherapy or pelvic radiation therapy.

When does it happen?

Perimenopause may start in a woman’s 40s. Menopause often starts around age 50. The process varies from woman to woman.

  • About half of all women stop menstruating by age 48.
  • By age 52, 85% of women will have reached menopause.
  • If a woman stops menstruating before age 40, it is called “premature ovarian failure.”
  • Women who have had one ovary surgically removed don’t experience menopause any earlier than women with two ovaries.
  • Ethnicity, marital status, genetics, and geography do not seem to influence menopause.
  • Smokers experience menopause an average of two years earlier than nonsmokers.

At menopause, estrogen levels decline. But estrogen production does not completely stop. The ovaries still produce a small amount of estrogen, as do fat cells and the adrenal glands.

How does menopause affect your health?

Estrogen and progesterone affect more than just the reproductive system. A decrease in these important hormones causes both short- and long-term changes.

For example, before menopause few women experience coronary artery disease. After age 50, women begin to develop the disorder at an increasing rate. By age 65 the risk of a heart attack is as great in women as it is in men.

Less estrogen is also associated with a loss of bone mass, causing bones to become thinner and more brittle. This condition is called osteoporosis, and can lead to painful bone fractures.

If you are a woman, menopause is a perfectly natural part of aging. If you are experiencing negative symptoms from menopause, speak with your doctor.

Can a woman get pregnant during perimenopause?

  • The claim: You can’t get pregnant during perimenopause.
  • The facts: Pregnancy during perimenopause is unlikely. But it’s not impossible.

It’s true that women are much less fertile during this stage of life. But that doesn’t mean there’s no chance of becoming pregnant. Perimenopause can last as long as 8 to 10 years. It typically begins when a woman is in her mid-40s. Menstrual periods become less regular, so it’s harder to predict when you might be ovulating. Until you are in full menopause—there is still the chance of conceiving a child.

  • For the record, it’s also possible, though not likely, to become pregnant while having your menstrual period. In other words, don’t rely on either having your period or being in perimenopause as birth control.