Endometriosis

Most people who come to us about endometriosis have already been told, more than once, that bad periods are normal. Some have been told it is stress, or a low pain threshold, or that nothing showed up on the scan so there is nothing to find. That history matters, because it shapes how long you have waited and how much you have had to argue. Endometriosis is a real, common, inflammatory disease with a hormonal driver, and it can be diagnosed and treated without your first having to prove it in an operating room.

What endometriosis is, and what it is not

Endometriosis is the presence of tissue resembling the lining of the uterus in places outside the uterus: on the peritoneum that lines the pelvis, on the ovaries, on the ligaments that support the uterus, and less often on the bowel, the bladder, or the diaphragm. These deposits respond to hormonal signals, bleed, provoke inflammation, and over years can lay down scar tissue that tethers organs to one another. It behaves as a chronic inflammatory condition with an estrogen-dependent driver. It is not an infection, it is not caused by anything you did, and it is not a psychological problem that has found a physical outlet.

It is common among people of reproductive age and is one of the leading contributors to infertility. It is also one of the most consistently delayed diagnoses in medicine; years usually pass between the first symptoms and a name for them. Much of that delay is not diagnostic difficulty. It is that severe menstrual pain has been treated as an ordinary feature of having a uterus rather than as a symptom that deserves a workup, so the question never gets asked.

Severity of pain does not track with stage of disease

Endometriosis is staged from I to IV based on what a surgeon sees at operation: the number, depth, and location of lesions and the extent of adhesions. That system was built to describe anatomy and to help predict fertility outcomes, and it does those jobs reasonably well. What it does not do is predict pain. Someone with a handful of superficial lesions and stage I disease can lose three days a month to it, while someone with stage IV disease and an ovary fused to the pelvic sidewall can have modest symptoms and come in only because conception is not happening.

This has a practical consequence. How much pain you report is not evidence for or against how much disease you have, and no one can reassure you out of your symptoms on the strength of a scan or an old operative note. Pain here comes from several sources at once: inflammation around the lesions, nerve fibers that grow into and around them, deposits sitting in nerve-rich places such as the uterosacral ligaments, and the changes that occur in the pelvic muscles and nervous system when pain has run for years.

The symptoms, including the ones people do not think to mention

Painful periods are what brings most people in, but they are rarely the whole picture, and the rest is often what makes the pattern recognizable. Timing is the most useful clue we have: symptoms elsewhere in the body that rise and fall with the menstrual cycle point toward endometriosis in a way that constant symptoms do not, so part of a first visit is sorting what is cyclical from what is not.

• Pain with deep penetration during sex, often worse in the week before a period and lingering afterward
• Bowel symptoms that are cyclical: pain with bowel movements, looser or harder stool, bloating that arrives with menstruation
• Bladder symptoms that are cyclical: urgency, frequency, or discomfort with a full bladder around the period
• Fatigue out of proportion to activity, clustering in the days before and during bleeding
• Difficulty conceiving, sometimes the presenting sign in someone with very little pain
• Pain that has spread across most of the month, which usually signals a secondary muscular component rather than worse disease

Several of these overlap with irritable bowel syndrome and with bladder pain syndrome. The overlap is genuine rather than a sign of diagnostic confusion, and having more than one of these conditions at once is common. Naming all of them matters, because treating the endometriosis alone leaves part of the pain untouched.

Why imaging can be normal, and why we no longer wait for surgical proof

Transvaginal ultrasound is a good test for some forms of endometriosis and a poor test for others. It reliably shows endometriomas, the cysts of old blood that form on the ovaries, and in experienced hands it can identify deep infiltrating disease behind the uterus or on the bladder. It is essentially blind to superficial peritoneal lesions, which are the most common form of the disease. MRI adds detail for deep disease and helps with surgical planning, but it shares that blind spot, and no blood test makes the diagnosis. A normal scan means your ovaries look normal and no obvious nodule is present. It does not mean you do not have endometriosis.

Laparoscopy with tissue confirmation remains the only way to prove the diagnosis with certainty. For most of the last century that certainty was treated as a prerequisite for treatment, which meant people waited years in pain for an operating room. Current US practice, consistent with ACOG guidance, is that endometriosis can be diagnosed clinically when the history is characteristic and treated empirically, with surgery reserved for those who need it. A response to medical therapy is informative in its own right.

A diagnostic laparoscopy is a decision about surgery. It is not a decision about whether to believe you.

Surgery still has clear indications: medical treatment that has failed or cannot be tolerated, an endometrioma or deep infiltrating disease on imaging, certain fertility situations, and a diagnosis that remains unclear after a thoughtful trial. When surgery is done, excision rather than surface ablation is generally preferred for deep disease, and the surgeon's volume and experience influence the result more than almost any other variable. It is fair to ask directly who will be operating and how often they do this particular work.

Treatment, in the order we usually try it

Treatment aims at the two things that matter to you: how much pain you have, and what you want from your fertility and when. Nothing available today cures endometriosis, and symptoms can return when treatment stops, which is worth knowing at the start rather than discovering later. What is achievable for most people is durable control of pain with a regimen they can live with, adjusted over the years as circumstances change.

NSAIDs started a day or two before the period rather than after the pain arrives are the first and least invasive step, and they work better than most people expect when timing and dose are done properly. Hormonal suppression is the mainstay. Combined hormonal contraception taken continuously so there is no withdrawal bleed is a common starting point; progestin-only options such as norethindrone acetate or the etonogestrel implant suit people who cannot take estrogen; and a levonorgestrel intrauterine device delivers progestin locally with little systemic exposure and often reduces both pain and bleeding. These are not interchangeable, and finding the one you tolerate frequently means trying more than one.

GnRH agonists and the newer oral GnRH antagonists suppress ovarian hormone production more completely and are an option when first-line treatment has not been enough. The trade-off is real: a low-estrogen state with hot flashes, vaginal dryness, and loss of bone density, which is why they are usually given with add-back hormone therapy and with attention to duration. In long-standing pain, pelvic floor physical therapy is often the missing piece. Muscles that have been guarding for years become a pain generator of their own, and no amount of hormonal suppression will release them.

Adenomyosis, the near neighbor that is often the real answer

Adenomyosis is endometrial-type tissue within the muscular wall of the uterus rather than outside it. It produces heavy, painful periods and a uterus that is diffusely enlarged and tender on examination. It is frequently mistaken for endometriosis, often coexists with it, and turns out to be the dominant problem in a fair number of people treated for endometriosis without much relief. It is also more visible on imaging, particularly on MRI and on a careful ultrasound done by someone looking for it. Treatment overlaps considerably: the hormonal IUD often works well, with uterine artery embolization, performed within our group, and hysterectomy at the other end of the range. We look for it in anyone whose periods are heavy as well as painful.