Menopause occurs when your ovaries stop producing estrogen, the hormone that controls the reproductive cycle. Anything that damages your ovaries or stops estrogen can cause premature menopause. This includes chemotherapy treatment for cancer or surgery to remove the ovaries. In these cases, early menopause is a side effect your doctor will prepare you for. But some women unexpectedly go into menopause early, even if their ovaries are still intact.
The average age for menopause in the United States is 51, according to the National Institute on Aging. Generally, most women experience onset between the ages of 40 and 60. Early menopause usually refers to cases where onset occurs before the age of 40. There are several known causes of early menopause, although sometimes the cause remains unknown.
When there’s no obvious medical reason for early menopause, the cause often lies in your genes. Researchers have determined that age at menopause onset is most likely inherited. Finding out when your mother started menopause can provide clues as to when you’ll start your own. If your mother started menopause early, then you are six times more likely than average to do the same. Yet genes tell only half the story.
Smoking can contribute to early menopause, due to its anti-estrogen effects. Several studies have indicated that long-term or regular smokers are likely to experience menopause sooner than the average age of occurence. According to the Mayo Clinic, on average, smokers start menopause one to two years earlier than non-smoking women.
Body mass index (BMI) is another possible factor in early menopause. Estrogen is stored in fat tissue. Very thin women have less estrogen stores, which can be depleted sooner, experts say. Other studies have indicated that a higher BMI could cause a late onset of menopause.
Certain defects in chromosomes can lead to early menopause. Turner syndrome is one such condition. This condition occurs when a girl is born with an incomplete chromosome. Women with Turner syndrome have ovaries that don’t function properly, often causing them to enter menopause prematurely.
Premature menopause can be a symptom of an autoimmune disease. These occur when the immune system attacks a part of the body, mistaking it for an invader. Inflammation caused by some autoimmune diseases, such as thyroid disease and rheumatoid arthritis can affect the ovaries. Menopause begins when the ovaries stop working.
Epilepsy is a seizure disorder that stems from the brain. A number of studies have found that women with epilepsy are more likely to experience premature ovarian failure (POF). POF leads to menopause. One study in particular found that in a group of epileptic women, about 14 percent had premature menopause, as opposed to 1 percent of the general population.
When you start menopause 10 or more years early, the most obvious concern is the end of your fertility. Yet there are other health worries too. In addition to its role in reproduction, the steady stream of estrogen to your tissues has many uses. Estrogen increases “good” HDL cholesterol and decreases “bad” LDL cholesterol. It also relaxes blood vessels. The hormone shields bones, preventing them from thinning.
Losing estrogen earlier than normal can put you at increased risk for:
- heart disease
- Parkinson’s-like symptoms
- premature death
These are all serious concerns that you should discuss with your doctor. Because of these risks, women who enter menopause early are often prescribed hormone replacement therapies (HRT).
On the plus side, starting menopause early might actually protect you against other diseases, particularly estrogen-sensitive cancers such as breast cancer. Women who enter menopause late (after age 55) are at greater risk for breast cancer than those who enter the transition earlier in life, because their breast tissue is exposed to estrogen for longer.