Similar to endometriosis, adenomyosis can cause pain, heavy bleeding, and trouble getting pregnant.

By Amanda Gardner
March 13, 2018

Too often, heavy, painful periods are shrugged off as part of being a menstruating woman. By the time things get bad enough to Google your symptoms, you’re not offered much help. “If you search ‘pelvic pain’ or ‘painful periods,’ the list of different possible diagnoses that go along with those symptoms–an encyclopedia couldn’t cover it!” says Benjamin M. Schwartz, MD, chairman of obstetrics and gynecology at Northwell Health’s Southside Hospital in Bay Shore, New York.

One of the lesser-known causes of this kind of pain is adenomyosis, which happens when the uterus lining–the endometrial tissue–grows into the muscle of the uterus. That displaced tissue continues to bleed monthly, which can result in heavy menstrual bleeding, painful periods, and an enlarged uterus. “When you have the endometrial glands in the muscle wall of the uterus, the uterus can’t function appropriately with the menstrual flow,” says Stephen J. Hilgers, MD, a gynecologic and reproductive surgeon at Houston Methodist Hospital.

Adenomyosis is thought to affect between 20% and 30% of women of childbearing age. Here’s what you should know about the condition–a close cousin of endometriosis.

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Adenomyosis symptoms

About one-third of women with adenomyosis actually don’t have symptoms. But of those who do, most experience heavy menstrual bleeding and pain around their periods, Dr. Schwartz says.

Some women with adenomyosis also have chronic pelvic pain, painful sex, or blood clots during their periods. The endometrial tissue that has grown in the uterus muscle can also lead to an enlarged uterus, though you may or may not be able to notice this.

Adenomyosis can also make it difficult to get pregnant, although it can be hard to separate adenomyosis from other causes of infertility, says Dr. Hilgers.

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Adenomyosis causes

There is no known cause of adenomyosis. Experts have some theories though. “For example, in a woman who’s had a C-section where the wall of the uterus has been cut, it’s possible that when the uterus heals, endometrial glands end up in the uterus wall,” explains. Dr. Schwartz.

While there’s little understanding of how the condition starts, it is clearly fueled by estrogen. Symptoms often go away when a woman reaches menopause, he adds.

Adenomyosis treatment

The only way to diagnose adenomyosis with certainty is to have surgery to remove the uterus, called a hysterectomy, and examine the organ under a microscope. Obviously, this isn’t an option for women who still want to get pregnant, so doctors rely instead on transvaginal ultrasounds and MRIs.

Adenomyosis is sometimes diagnosed by accident, maybe during surgery or an imaging procedure for another condition, says Dr. Hilgers. If you don’t have any symptoms or only mild symptoms, you might not need any treatment.

If you do have symptoms, your treatment will be highly individualized, says Dr. Hilgers. For some women, hormonal birth control in the form of the pill, patch, or an IUD may help.

Some women opt for procedures for adenomyosis, including endometrial ablation, which destroys the lining of the uterus, or uterine artery embolization, which cuts off the blood supply to the uterus. In women who still have years before menopause, doctors may recommend treating adenomyosis with a hysterectomy if the pain is severe. 

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“Adenomyosis is not life-threatening, though it may negatively impact quality of life,” says Dr. Schwartz. “If you didn’t want to have a procedure, it’s okay to live with it until you go into menopause.” If you choose to live with it, your doctor might suggest using anti-inflammatory medications like ibuprofen to help ease the pain.

Because irregular, painful bleeding can sometimes be symptoms of serious conditions like cancer, doctors may biopsy tissue in women who are closer to menopause. This helps them rule out those conditions before giving the okay to live with adenomyosis until symptoms subside.

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Adenomyosis vs. endometriosis

Adenomyosis shares some characteristics with endometriosis, which is when the uterine lining grows in areas outside the uterus. “With endometriosis, you have [endometrial tissue] outside the uterus, like on the bowel, bladder, and fallopian tubes,” says Dr. Hilgers. “Adenomyosis is a similar process, but within the uterus muscle wall.”

You can even have adenomyosis and endometriosis at the same time, but they are considered separate conditions. The symptoms of both are similar, he adds, and both conditions are stimulated by estrogen. Both can make pregnancy difficult too; endometriosis is the leading cause of infertility in women.