Menopause is the end of a woman's menstrual cycle and fertility. It happens when the ovaries no longer make estrogen and progesterone, two hormones needed for a woman's fertility, and periods have stopped for 1 year.
Menopause happens naturally with age. But it can also happen as a result of surgery, treatment of a disease, or illness. In these cases it is called induced menopause or premature ovarian failure.
Here's what does -- and does not influence the age at when a woman reaches menopause.
The Top Factor
There are a number of factors that affect a woman’s age at menopause, but one is more important than any other: the age her mother experienced menopause.
“Menopause is strongly genetically linked, so you’re very likely to fall within a few years either way of the age your mother was at menopause,” says Nanette Santoro, MD, director of the division of reproductive endocrinology and infertility at the University of Colorado-Denver School of Medicine and a member of the board of directors of the American Society for Reproductive Medicine.
This isn’t always true, of course. Some women reach menopause at an unusually early age -- before 45 or so -- with no known cause, which could be the result of an inherited issue or a one-time genetic mutation. “These can be random events, but can also be passed on," says Howard Zacur, MD, PhD, who directs the reproductive endocrinology and infertility division at Johns Hopkins School of Medicine.
So if your mother reached menopause at 40, but her sisters and your grandmother were all around the average age of 50, it’s unclear whether you’ll follow her path or theirs.
But if most of the women in your family, your mother included, reach menopause early, late, or somewhere in the middle, you can eye your calendar with some degree of confidence.
Menopause Age: 4 More Influences
Your mother's age at menopause is a key factor, but not the only one. Here are four others to consider:
Smoking. No other lifestyle factor does more damage to your ovaries than smoking. So if you smoke and your mother didn’t, you’ll probably reach menopause earlier than she did. If she smoked and you don’t, you probably reach menopause later than she did.
Chemotherapy. Most forms of chemotherapy used in younger women are at least mildly toxic to the ovaries. Many women go through temporary menopause while undergoing chemotherapy; if cycles do return (they don’t always), you can still expect to reach regular menopause a couple of years earlier than you otherwise would have.
Ovarian surgery. “The more you operate on the ovaries, the more healthy tissue gets damaged,” says Marcelle Cedars, MD, director of the division of reproductive endocrinology at the University of California, San Francisco, School of Medicine. So if you’ve had diagnostic surgery for endometriosis, for example, Cedars recommends using medical options (such as hormonal suppression) to treat the condition in order to avoid repetitive surgeries.
Ethnicity. “Certain ethnic groups may have menopause at slightly different ages,” says Santoro. “Hispanic and African-American women reach menopause a little earlier, and Chinese and Japanese women a little later, than the average Caucasian woman, who reaches menopause at about age 51.5.” Those are averages; every woman is different.