People often categorize endometriosis as a “women’s health” issue, leading many to think it’s a disease of the female reproductive organs — but it’s not. Here’s what the research says and when to contact a doctor.

“Anyone can have endometriosis,” says Heather Jeffcoat, DPT, author of ”Sex Without Pain: A Self-Treatment Guide To The Sex Life You Deserve.”

However, cisgender women and other people assigned female at birth (AFAB) are much more likely to develop endometriosis than cisgender men and other people assigned male at birth (AMAB).

For reference, endometriosis affects roughly 190 million reproductive-age women and girls worldwide. There are less than 20 documented cases of endometriosis in boys or men.

You’ll notice that the language used to share stats and other data points is pretty binary, fluctuating between the use of “male” and “female” or “men” and “women.”

Although we typically avoid language like this, specificity is key when reporting on research participants and clinical findings.

Unfortunately, the studies and surveys referenced in this article didn’t report data on, or include, participants who were transgender, nonbinary, gender nonconforming, genderqueer, agender, or genderless.

There’s very little research on endometriosis. There’s even less research on endometriosis in cisgender men and other AMAB folks.

The most recent research on the topic was published in 2018. At the time, only 16 cisgender men had ever been diagnosed with the condition.

One 2022 expert commentary acknowledges that endometriosis affects trans men and other transmasculine folks, but more research is necessary to understand how many people endometriosis impacts.

Endometriosis occurs when uterine-like cells grow on or around your pelvic organs, including the:

In rare cases, endometriosis can also grow on or around the:

  • brain
  • eyes
  • nasal cavity
  • lungs
  • liver
  • kidneys
  • pancreas
  • skin, including surgical scars
  • nerves
  • vagina
  • cervix

Your individual symptoms, diagnosis, and care plan will vary, depending on the affected area(s). Consult a doctor or another healthcare professional to learn more.

According to Jeffcoat, prolonged exposure to estrogen therapy is the main risk factor for endometriosis in cisgender men and other AMAB folks. Estrogen therapy was once a common treatment for prostate cancer.

Some researchers suspect that obesity could be another risk factor, as it can create a systemic increase in estrogen levels.

“Prolonged surgical inflammation and liver cirrhosis are other noted risk factors for endometriosis cited in the literature,” says Jeffcoat.

Endometriosis could also result from things that occur before birth when an individual is still an embryo, adds Jeffcoat.

Müllerian ducts, for example, form early on in fetal development. Müllerian ducts go on to form the female reproductive organs for most AFAB folks. The structure typically atrophies and disappears completely in AMAB folks.

Some believe that Müllerian ducts can turn into endometrial-like cells if they don’t atrophy completely before birth, she says.

Given how rare it is for AMAB individuals to have endometriosis, it can be tricky to get an endometriosis diagnosis.

If you’re experiencing any of the following symptoms — and you don’t have any other diagnosis — consider taking with a clinician about endometriosis:

If a medical professional says that you have low sperm motility, be sure to discuss endometriosis as a potential cause with your clinician. Endometriosis is may decrease sperm motility.

“Abdominal and pelvic pain are classic symptoms many of these patients share, some of whom can experience these pains all month long,” says Jeffcoat.

Other symptoms common among transgender men and other AFAB folks include:

There’s a widespread misconception that hysterectomy can cure endometriosis in AFAB folks.

“Having a hysterectomy or surgically removing the uterus and ovaries will not cure endometriosis because endometriosis is a disease outside of the uterus,” says Jeffcoat. “A hysterectomy will only remove adenomyosis.”

Adenomyosis occurs when endometrial tissue grows into the muscle of the uterus.

“Removing the ovaries and uterus will not take care of endometriosis that may be on your bladder, rectum, diaphragm, or elsewhere,” she says.

If you’re experiencing any unexplained or unusual symptoms, it’s important to speak with a healthcare professional.

Ideally, a healthcare professional who’s gender-inclusive *and* well-versed in endometriosis.

To find a gender-affirming provider near you:

“Don’t let a provider turn you away with a recommendation of ibuprofen,” says Jeffcoat. If one does, “please seek out a specialist that will take a look at your history and recommend the proper tests to determine the cause of your pain.”

Does endometriosis affect men and women differently?

Endometriosis affects all people differently, depending on where it grows. In people who menstruate, for example, endometriosis may cause painful periods.

How does endometriosis typically present in men?

“The most common way endometriosis presents, regardless of whether you’re assigned male or female at birth, is abdominal and pelvic pain,” explains Jeffcoat.

Can endometriosis affect your fertility if you have a penis and testicles?

Given the current body of research, it’s hard to say.

“It has been found that inflammation from endometriosis can affect sperm motility,” says Jeffcoat.

Experts have linked decreased sperm motility with infertility, but they need more research to understand how endometriosis specifically can affect male reproductive organs.

Can endometriosis affect your fertility if you have a vulva and vagina?

Yes.

“Fertility challenges are frequently found in those assigned female at birth,” says Jeffcoat. In fact, women who experience infertility are 6–8 times more likely to have endometriosis.

Jeffcoat explains that, for many, an early endometriosis diagnosis leaves room to consider egg or embryo freezing as a way to have biological children later on.

Endometriosis can affect anybody, regardless of gender identity, sex assigned at birth, or current reproductive organs. This includes cisgender men and others assigned male at birth.

If you’re experiencing symptoms associated with endometriosis, consult a doctor or another healthcare professional. They can help you identify the cause of your symptoms and advise you on any next steps.

Gabrielle Kassel (she/her) is a queer sex educator and wellness journalist who is committed to helping people feel the best they can in their bodies. In addition to Healthline, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.