5 things you need to know about the “evil twin sister” of endometriosis

Despite growing public awareness of endometriosis, with prominent figures including Lena Dunham and Molly Mae, the “evil twin sister,” adenomyosis, remains overlooked.

While the NHS has a whole webpage explaining what endometriosis is, there is currently no equivalent for its sister condition.

Read on for five things you should know.

It’s not the same as endometriosis

Both endometriosis and adenomyosis occur when the lining of the uterus (known as the endometrium) grows out of place, but there are major differences between the two.

In endometriosis, rogue tissue invades areas outside of the uterus. While the extent of the growth varies from patient to patient, it can affect areas such as the bladder, bowels, ovaries, and even the lungs. Adenomyosis, on the other hand, causes rogue tissue to be buried inside the muscular wall of the uterus.

It is possible to suffer from both conditions at the same time.

Symptoms include bloating, heavy periods, and pelvic pain

Due to the invasive growth of the endometrium, adenomyosis is characterized by an enlarged uterus. During menstruation, the embedded tissue swells and bleeds, typically causing a variety of symptoms (although some women are asymptomatic).

According to a patient booklet published by University College Hospital, sufferers commonly have painful and irregular periods, with more than half experiencing heavy bleeding. Chronic pre-menstrual pain and feelings of heaviness and discomfort in the pelvis are among other possible symptoms.

Less commonly, adenomyosis can cause bloating, pain during intercourse, and pain related to bowel movements. All symptoms should cease after menopause.

It affects 1 in 10 women

The condition is believed to affect 10% of women in the UK. This makes it as common as endometriosis, although it is more common in women aged 40 to 50 and those who have been pregnant before. While the cause of the condition isn’t known, UCH says “genetics and certain hormones may play a role.”

In terms of long-term effects, the North Bristol NHS Trust say adenomyosis does not appear to reduce the chances of pregnancy, however it has been linked to an increased risk of miscarriage and stillbirth.

Treatment options are limited



For women with mild symptoms, trying to get pregnant or approaching menopause, the North Bristol Trust says treatment may not be necessary, but for those seeking symptom relief, they recommend medicines to reduce pain and bleeding and hormonal interventions such as the contraceptive pill.

The only “cure” is a surgical procedure that involves removing the uterus (hysterectomy), although this is a last resort. The Bristol-based trust also offers an alternative surgery that involves cutting off the blood supply to the growing endometrium, forcing it to shrink, but neither procedure is advisable for women who want to get pregnant in the future.

It can take years to diagnose

The condition is typically diagnosed using MRIs and ultrasound scans, but the NHS says adenomyosis can take ‘a long time, even years, to diagnose’ because ‘symptoms and severity can vary between women’.

The frequent dismissal of women’s gynecological symptoms means that the signs of adenomyosis can be confused with “normal” menstruation or even other conditions such as endometriosis. Anecdotal reports from sufferers suggest that misdiagnosis is common.

Gabrielle Union, one of the few celebrities to have publicly identified the condition, suspects her condition has gone undiagnosed for years.

Speaking at a conference in 2019, Union explained: “The gag is that I had [adenomyosis] when I was in my early twenties, and instead of someone diagnosing me, they were like, ‘Oh, you have periods that last nine or 10 days and you’re bleeding through pads at night? Not a mere inconvenience… maybe there’s something more there.’”

Earlier this year, the charity Tommy’s reported that the condition could be ‘underdiagnosed’ after a review of existing studies found that ‘mild’ cases could be missed by doctors using current diagnostic methods .

“There should be training for physicians and sonographers to diagnose adenomyosis using standardized criteria,” said Dr. Ishita Mishra, review leader.

“Being able to identify this condition using a uniform set of criteria would therefore help give us a true picture of the numbers involved and a better understanding of the impact of this condition,” Mishra explained.

If you have any health problems, you should always contact your GP in the first instance.

There is also information available via NHS Scotland OR Endometriosis UK.

Leave a Reply

Your email address will not be published. Required fields are marked *