First, two quick definitions, because I use both words a lot below.

Endometriosis is when tissue like the lining of the uterus grows outside the uterus. It bleeds and swells each month, and it hurts. Hypermobility means your joints move farther than they should. It often comes from a difference in your connective tissue — the material that holds your body together. The most common type is hypermobile Ehlers-Danlos syndrome, or hEDS.

Now, the research. I want to be honest here, because the internet has gotten ahead of the science.

The best study we have looked at 386 women with hEDS. A specialist women’s health doctor examined every one of them. Endometriosis was found in 6%. That is about the same rate you would find in any group of women. So no, hypermobility does not appear to cause endometriosis (Hugon-Rodin and colleagues, Orphanet Journal of Rare Diseases).

But look at the rest of what that study found. Out of those same 386 women:

Read that again. Three out of four hypermobile women have heavy, painful periods. Almost half have pain with sex. And most of them do not have endometriosis at all.

Here is why that matters so much. From the outside, hypermobility can look almost exactly like endometriosis. That hurts women in two different ways. Some hypermobile women really do have endometriosis, but nobody believes them. Their pain moves around and seems “too big” for the tests, so doctors write it off. Other hypermobile women do not have endometriosis, but they have surgery after surgery looking for it. The doctors who ran that study said it plainly: knowing what hypermobility looks like helps tell the two apart, and it saves women from operations they never needed.

And endometriosis is already slow to diagnose. A 2024 review found that women wait about 6.8 years on average to get an answer. Some waited less than two years. Some waited more than eleven (Health Care for Women International, 2024). Add an undiagnosed connective tissue problem on top, and that wait gets even longer.

Let me be clear. Excision surgery, where a skilled surgeon cuts out the endometriosis, is the right operation. I send patients for it all the time. But a lot of women still hurt afterward, and that is usually not the surgeon’s fault.

Think of your nervous system as having a volume knob for pain. When pain signals come from your pelvis over and over for years, your body turns that knob up. It is trying to protect you. The problem is that after a while, the knob stops turning back down. Now some of the pain is coming from the alarm system itself, not just from the tissue.

Doctors call this central sensitization. Pain that keeps going after the endometriosis is treated has a name too: nociplastic pain. It simply means real pain made by a nervous system that is stuck on high (review of endometriosis pelvic pain, PMC). A review of many studies found this same pattern in endometriosis again and again (PMC).

Here is the frustrating part. We can measure this before surgery with a short questionnaire called the Central Sensitization Inventory. Women who score high on it tend to get less relief from the operation (JAMA Network Open). It takes about ten minutes to fill out. It would tell a surgical team which patients need a second plan running alongside the surgery. Almost nobody uses it.

Now add hypermobility. Hypermobile women often arrive at surgery with that volume knob already turned up. They have spent years sending pain signals from a different source: joints slipping out of place, small strains, muscles clenching to hold things steady. Many also have trouble with the nerves that control heart rate and blood pressure, which keeps the whole body on edge. If you are not sure where you fall, start with our guide to getting diagnosed and our plain-language piece on understanding dysautonomia.

A hypermobile woman with endometriosis does not have one pain problem. She has two, and they both feed the same amplifier.

One more word to know. Fascia is the web of connective tissue that wraps around every muscle and organ in your body. Picture the thin white film you peel off a chicken breast. That is fascia. It is supposed to slide and glide so your muscles can move freely.

This next finding changed how I examine these patients. When researchers carefully check women who have endometriosis and ongoing pelvic pain, the sore spots are not only near where the endometriosis was. These women have tight, painful muscles and fascia all over the area — a clenched pelvic floor, tender knots in the belly wall, and skin that hurts to touch in places far from any lesion (cross-sectional study, PMC). Muscle and fascia pain plays a part in a large share of all chronic pelvic pain.

Here is the catch. You find this with your hands, not with a scan. It takes about four minutes of careful pressing on the belly wall, the pelvic floor, the inner thighs, the hip flexors, and the low back. It does not show up on an MRI. It does not show up during surgery. And in a fifteen-minute appointment, nobody does it.

So a woman whose main pain source is tight, stuck fascia gets told her scan is clean and her surgery went fine. She leaves with no answer.

In a hypermobile body, this matters even more. When your ligaments do not hold your joints steady, your muscles and fascia take over that job. They do it by staying switched on all the time. Muscles that never relax make fascia stiff and sticky. Stiff fascia does not glide, so the tissue gets pulled in ways it should not. That pulling makes the muscles clench even harder. Around and around it goes.

The pelvis is the worst place for this loop. Your pelvic floor already has three jobs: holding you upright, controlling your bladder and bowels, and sex. Now it is being asked to steady your whole frame too. That is not a job it was built for.

I wrote the full explanation of how this works on our main site: Endometriosis, Hypermobility and Fascial Pain. If you only follow up on one part of this article, make it that one.

Mast cells are immune cells. When they fire off, they release histamine and other chemicals. That is what happens during an allergic reaction. Some people have mast cells that fire too easily and too often. That condition is called mast cell activation syndrome, or MCAS.

MCAS shows up with hypermobility often enough that I check for it in every patient. It turns out mast cells matter in endometriosis too, which makes this overlap a real problem.

Endometriosis spots hold far more mast cells than a woman’s normal uterine lining does. In the deepest kind of endometriosis, those mast cells are more active, and they sit right up against nerve endings. Estrogen is what sets them off. Endometriosis feeds on estrogen, and the estrogen in those spots triggers the mast cells directly (Frontiers in Immunology, 2022). The chemicals they release then pull more nerve endings into the area and make those nerves more touchy (Frontiers in Immunology, 2023). Women with more mast cells in their lesions report more pain.

So a hypermobile woman with MCAS has two mast cell problems in one body. And one of them rises and falls with her own hormones every month.

That explains something my patients describe all the time and never get an answer for. The flushing, the nausea, the headaches, the joint pain — all of it getting worse at the same point in the cycle, every cycle. That is not you being dramatic about your period. That is inflammation on a schedule.

The biggest mistake I see is treating this as one question with one answer. It is really four questions. And you can be a yes on all four at the same time.

Answer these one at a time and the treatment plan almost writes itself. Lump them together and you end up doing a third surgery on a woman whose real problem is a pelvic floor that has not relaxed in six years.

The full reasoning behind this workup is on our main site, in the deep dive on endometriosis, hypermobility and fascial pain.

If it turns out your nervous system has turned the volume up, the medication plan changes.

Ibuprofen and similar drugs work on swelling in tissue. Opioids work on a different set of switches. Neither one does anything about the low-grade inflammation inside the nervous system that keeps the volume knob stuck. That is the gap.

Low-dose naltrexone is aimed right at that gap. For a hypermobile woman with monthly pelvic pain, mast cell trouble, and deep fatigue, it is often the best thing to try first. It is cheap, most people tolerate it well, and it targets the right problem. It also works well for people who react to everything, as long as you start at a very low dose. It is used off-label, which means it is not officially approved for this, and it should be prescribed and monitored by a doctor.

Hormone treatment still has a place, and that stays with your gynecologist. I want you to understand who handles what. Hormone treatment can quiet the monthly inflammation. Surgery can remove the lesions. But neither one fixes a nervous system stuck on high or a pelvic floor that has been braced for years. Those need their own treatment, at the same time. Skip them and your relief stops halfway.

FIT Therapeutics is the hands-on, drug-free side of our program. We built it for hypermobile bodies, and for people who tried regular physical therapy and did not get better. It runs under the medical oversight of The Fascia Institute (more here). That means your therapy targets what a doctor actually found on your exam.

It starts with one long session with a specialist. That visit combines hands-on fascia work, recovery tools, and movement retraining, all matched to your body (see the fascia care pathway). For pelvic pain, here is what earns its place:

You do not need a referral. You can book yourself in. Our main hands-on clinic is in the Garden District in New Orleans (details here). Los Angeles patients get the same care at our Beverly Hills clinic, described below. You can see everything we offer on the Fascia Institute services page.

To be clear about what we do: we are not a gynecology office, and we do not perform endometriosis surgery. We handle the half of this problem that usually gets skipped. That means diagnosing the connective tissue condition, checking whether your nervous system has turned the volume up, examining your muscles and fascia by hand, and building a plan from what we find. We work alongside your gynecologist or surgeon, not instead of them.

The Beverly Hills Hypermobility Clinic is the Los Angeles home of The Fascia Institute and Treatment Center (announcement here). We see patients from all over Los Angeles, California, and the West Coast. This is doctor-led care for hypermobility, EDS, POTS, MCAS, metabolic problems, fascia pain, and unstable joints.

Beverly Hills Hypermobility Clinic
415 North Crescent Drive, Suite 130
Beverly Hills, CA 90210
(424) 378-3488

Now accepting new patients. Dr. Jacques Courseault, MD is board-certified in Physical Medicine and Rehabilitation and founded The Fascia Institute. He sees patients in both New Orleans and Beverly Hills.

Not sure what to bring or what happens first? Read next steps. If you live outside California, check our directory of hypermobility and EDS specialists.

Three things to remember.

Hypermobility can look just like endometriosis. Three out of four hypermobile women have heavy, painful periods without any endometriosis at all. That is why some of us get missed for years, and why others get surgeries we never needed.

Pain that lasts after surgery is usually not the endometriosis coming back. It is usually a nervous system stuck on high, tight muscles and fascia, or both. A doctor can find both of those by examining you. Both can be treated.

Your fascia is the part nobody looked at. In a body where the ligaments do not hold, fascia is doing a job it was never built to do.

None of this means your endometriosis was not real. It does not mean the surgery was a waste. It means the operation fixed one of your problems, and you have been asked to live with the rest. You should not have to.

Read the full explanation at Endometriosis, Hypermobility and Fascial Pain. Browse more on our hypermobility and EDS blog. Or come see us.

Medical disclaimer. This article is for learning. It is not medical advice, and it does not replace a visit with your own doctor. Endometriosis is diagnosed and treated with surgery by gynecologists. The Fascia Institute and Treatment Center does not perform that surgery and does not replace gynecology care. Do not start, stop, or change any medicine or treatment based on this article. See a doctor if you have new or changing pelvic pain, unusual bleeding, or pain during sex.

Written by Jacques Courseault, MD (Dr. J). He is board-certified in Physical Medicine and Rehabilitation, and he is the CEO and Medical Director of The Fascia Institute and Treatment Center.