Endometriosis: Not Just Bad Periods.
Reviewed Dr Jo Mackson, MBBS FRACGP
Published August 2026
Reading time About 8 minutes
What Endometriosis Actually Is
Endometriosis is a chronic inflammatory disease in which tissue similar to the lining of the uterus grows outside it: on the ovaries, on the peritoneum (the membrane lining the abdominal cavity), on the ligaments holding the uterus in place, and on the outside of the bowel and bladder.
You have probably been told it is the lining of the uterus growing in the wrong place. That shorthand is close enough to be memorable and wrong enough to matter. The tissue is similar to the endometrium but not identical. This endometrial-like tissue grows on the surface of, and sometimes in the walls of, pelvic organs. These lesions are often responsive to your normal reproductive hormones, can produce oestrogen locally, recruit new blood vessels, and provoke a strong inflammatory response from the surrounding tissue. This is not a case of “tissue in the wrong spot”. It is a complex, multifaceted disease with effects that spread far beyond the uterus.
Around 1 in 7 Australian women born in the mid-1970s had been diagnosed with endometriosis by their mid-to-late forties, and the true figure is possibly higher, given the condition is so consistently underdiagnosed.
Why It Hurts
Endometriosis causes pain through several mechanisms running at once, which is why treating only one of them so often leaves a woman still in pain.
Some lesions respond to the hormones of your cycle and bleed microscopically, but the blood does not leave through the cervix and vagina the way a period does. Inflammatory signals and repeated tissue injury irritate nearby nerves and tissues, and over time can cause scarring and adhesions. For some women this pain tracks the cycle and peaks around bleeding. For others it becomes persistent, or arrives with sex, bowel motions, urination or physical activity.
Inflammation spreads beyond the lesions themselves, affecting the whole pelvic environment and sometimes with effects noted throughout the body. This is the flare women describe as feeling generally unwell rather than sore in one spot. The fatigue, aching and brain fog that come with it are part of the inflammatory picture.
The mechanism almost nobody has had explained. When tissue is inflamed month after month for years, the nerves supplying it start sending pain signals at lower thresholds, and the spinal cord and brain become more responsive to them, so sensations that once passed unnoticed may now register as pain. It means the nervous system can keep producing pain after the lesions are treated or removed. The pain is real. The signals are real.
Scar tissue can tether organs to one another, so that a full bladder, a bowel motion or sex causes pain at any stage of the cycle. And pelvic pain from any cause leaves the pelvic floor tight and reactive, at which point it becomes a source of pain itself.
All of which explains something women are rarely told: the pain does not always match the scan, and surgery does not always remove it.
How It Shows Up
The most common presentation is period pain severe enough to organise your life around: lying down with a heat pack, taking days off, planning holidays and events around when you bleed. For some women the pain also stops being confined to the period, arriving before the bleeding starts or continuing after it stops. Pain becoming less tied to bleeding is one of the patterns worth investigating.
Then there is deep pain with sex, felt high in the pelvis rather than at the entrance to the vagina. It is badly under-reported, because women are embarrassed or have been told to relax. Please raise it anyway. Bowel and bladder symptoms that follow the cycle are another sign worth acknowledging, and for many women the first sign is difficulty conceiving. If your periods have ever felt worse than you think they should be, that is enough of a reason to ask a doctor to review your history.
Getting Diagnosed in 2026
For most of the last century, an endometriosis diagnosis meant surgery, as unless endometriosis was seen under the microscope, it “wasn’t there”. That is no longer the position of Australian or international guidelines. RANZCOG here, and ESHRE internationally in their 2022 update, now hold that a presumed or clinical diagnosis can be made, with or without imaging support, and that treatment can begin on that basis alone.
The weight sits back where it belongs, on the history: how your pain tracks your cycle, how it has changed, whether there is pain with sex, bowel motions or urination.
The first imaging investigation is a transvaginal pelvic ultrasound, but not all scans are equal. A standard scan by a general sonographer is not the same as an endometriosis-focused scan by a pelvic sonographer with special training, sometimes called a DIE scan (Deep Infiltrating Endometriosis scan). What it can detect well is endometriomas and deep infiltrating disease, but even the best DIE scan cannot always reliably see superficial disease, which is the most common form of all. So a normal ultrasound does not rule endometriosis out. MRI can also be useful, particularly in women who have never been sexually active, for whom a pelvic ultrasound would be too invasive.
There is also currently no blood test that diagnoses endometriosis. There is exciting work being done in this space, but as of yet none are approved in Australia for diagnosis.
In Australia, the average time between first symptoms and diagnosis runs to between 6.5 and 8 years. Not because endometriosis is hard to diagnose, but because the symptoms have been normalised for generations, by the medical profession, by the culture, and eventually by women about their own bodies.
If your pain fits what you have read here and you have not had a proper workup, start with a GP appointment and a specific request: I would like to be investigated for endometriosis.
If you have asked before and been dismissed, we are sorry. That was not acceptable. What passed for reasonable practice a decade ago is not reasonable practice now.
What Treatment Actually Involves
Most women diagnosed with endometriosis ask the same question first: “Does this mean I need to have surgery?” We have been led to believe it is the only answer to endometriosis. In practice, most women with endometriosis, apart from those with deep infiltrating disease, do not need surgery. Endometriosis is a chronic inflammatory condition, and removing it does not cure it. The aim is to use treatment to control symptoms, manage fertility, and protect quality of life across decades.
Treatment targets different parts of the problem.
| What it targets | What that means |
|---|---|
| Disease activity and inflammation | Hormonal therapy. Suppressing ovulation, or providing steady progestogen exposure, reduces lesion activity, inflammation and pain. This includes the combined pill, the progestogen-only pill, other forms of oral progestogens, the hormonal IUD (Mirena) and Implanon. Beyond these sit medications that suppress hormonal signals coming from the brain. |
| Inflammatory pain | Anti-inflammatory medication. Underpins almost every plan, and works best started a day or two before the pain escalates. |
| Pelvic floor dysfunction | Pelvic floor physiotherapy. In our view the most under-prescribed treatment for endometriosis pain. A physiotherapist specialising in chronic pelvic pain can release trigger points and retrain a pelvic floor that has spent years being overactive. |
| Pain sensitisation | Pain neuroscience and pain psychology. Targets the sensitisation rather than the lesions causing the pain. This works not because the pain is psychological. Rather, it is a biological treatment for a biological change. |
| Structural disease, selected fertility issues, or symptoms not responding to other treatment | Surgery. Enters the conversation when medical management has not given enough control, when deep disease is causing structural problems, or when fertility seems to be affected. |
| The foundations | Nutrition, movement, sleep, alcohol and stress. We are not going to suggest a good night’s sleep and a brisk walk will make you good as new, but they are the platform everything else sits on, and they do have measurable impact on both pain and quality of life. |
Fertility: The Bit Everyone Googles First
Fertility is what most women want to read about first, and where the information online is at its most frightening. The headline message is: having endometriosis does not, however, mean you are infertile. Around 30 to 50% of women with endometriosis may experience some degree of subfertility, compared with 15% of couples generally. But that leaves between half and two-thirds of women with endometriosis who have no significant fertility problems.
Where it does affect fertility, it works through several routes: adhesions distorting the anatomy, endometriomas reducing ovarian reserve, and an inflammatory pelvic environment that can affect ovulation, fertilisation and implantation. That last one is hardest to measure, and probably explains why even mild disease is sometimes linked to subfertility.
For most women, trying to conceive naturally is the right place to start. What changes is how long to keep trying before asking for help. The “try for twelve months” rule most women have heard applies to those under 35 with no known reason for difficulty conceiving. Endometriosis is a known reason, which means for most women if it has been six months without a pregnancy, that is the point to seek review, rather than waiting out the year. Where deep infiltrating disease is already known, there is no reason to wait even that long, not because conception is unlikely, but because surgery may be required as part of fertility support and planning that takes time. Whether to operate before trying, or before IVF, is also a nuanced decision, because surgery helps fertility for some women but for others it might not, and worse, may ultimately impact ovarian reserve.
If you have endometriosis and are not trying to conceive now but think you might want children later, talk to your doctor early rather than when you start trying.
Fertility preservation is an important consideration for some women with endometriosis, as knowing your options and having conversations about your fertility early can make all the difference in achieving the family you desire.
So there you have it. Our Mini Guide on endometriosis. If we’ve left you feeling at all curious about the deeper science, or wanting a proper walk through the management options, our Deep Dive is where to go next.
This Mini Guide is the taste test of endometriosis. The Deep Dive is the full degustation. It covers every tasty morsel: why the woman with the mildest disease on paper can be the one in the most pain, what surgery can and cannot fix, and what the evidence actually says about the endo diet.
It is long. It is detailed. It is the education on this condition we think every woman should have had years ago. We are not going to insist you read it. Life is busy, and ‘long-form medical education’ is not on every woman’s reading list. But if you ever find yourself wondering, the Deep Dive is here when you are. Read it here.