Story
Endometriosis
Last updated
In one pass Endometriosis is tissue similar to the lining of the uterus growing outside the uterus, most often on the ovaries, on the lining of the pelvis (the pelvic peritoneum), and in the pouch between the uterus and the rectum.
Educational content, not medical advice — consult a clinician.
Story path
Chapter 1
What it is
Endometriosis is tissue similar to the lining of the uterus growing outside the uterus, most often on the ovaries, on the lining of the pelvis (the pelvic peritoneum), and in the pouch between the uterus and the rectum. This tissue still follows the menstrual hormones: every month it swells, bleeds and becomes inflamed, but the blood has no way out, so deep in the pelvis it keeps irritating, scarring and sticking tissues together. That is why the pain is deep and widespread, not like pain on the surface of the belly.
It is not a fatal disease, and there is currently no cure; medicines and surgery can keep it under control.
A few situations call for medical care the same day: sudden severe abdominal pain (possibly a ruptured or twisted ovarian endometrioma, the blood-filled cyst endometriosis can form on an ovary), heavy bleeding with dizziness or a racing heart, and abdominal pain or bleeding during pregnancy.
It is not a fatal disease, and there is currently no cure; medicines and surgery can keep it under control.
A few situations call for medical care the same day: sudden severe abdominal pain (possibly a ruptured or twisted ovarian endometrioma, the blood-filled cyst endometriosis can form on an ovary), heavy bleeding with dizziness or a racing heart, and abdominal pain or bleeding during pregnancy.
Background · How common it is, and what kind of disease
WHO estimates that it affects about 10% of women of reproductive age, roughly 190 million people worldwide. At heart it is an estrogen-dependent disease with chronic inflammation. It is not internal heat, not a cold womb (two ideas from traditional Chinese medicine), and not all in your head (WHO 2023; Zondervan 2020).The Critchley 2020 review describes menstruation itself as a hormone-orchestrated shedding and repair of tissue. The misplaced lining-like tissue still follows the same orders, but its blood has no exit through the cervix, so the inflammation and scarring happen deep in the pelvis. That is where the deep, widespread pain comes from.
It can be effectively controlled (with medicines or surgery), with the goals of controlling pain, protecting fertility and improving quality of life. There is currently no cure, but that does not make it a fatal disease.
Clinical · Worsening period pain is only the start
Typical signs include period pain that keeps getting worse, chronic pelvic pain (not fully gone even after a period ends), pain during sex, pain when passing stool or urine, heavy bleeding and profound fatigue; for some women, the first sign is infertility (Zondervan 2020).Many women have been brushed off since their first period with "just put up with the cramps". But if the pain is bad enough to miss work, is not controlled by painkillers, and even spreads into sex, bowel movements or urination, it may not be ordinary period pain. This is not a diagnosis; it is a reason to ask a doctor to take a proper look.
The rest of this story covers, in order: how it happens, and what about its cause is still unknown (Fed by estrogen, cause still unclear); why so many people wait years to be seen (Late diagnosis and what it costs); how the estrogen thread shapes treatment; how much nutrition can really help; and finally a list of things you can do yourself, and when you must see a gynecologist.
Chapter 2
Fed by estrogen, cause still unclear
Two things about endometriosis are fairly certain, and one must honestly be called uncertain.
Fairly certain: the lesions depend on estrogen to survive, and they make estrogen on the spot; estrogen drives pain- and inflammation-producing prostaglandins, and the prostaglandins push the lesion to make more estrogen, a loop that amplifies itself. At the same time, the lesions respond poorly to progesterone, which is supposed to be estrogen's brake, so the brake fails.
Still uncertain: the cause. Retrograde menstruation, blood flowing backward into the pelvis during a period, is the classic explanation, but about 90% of women have some backflow and only about 10% develop the disease, so backflow alone cannot explain whose cells survive.
Fairly certain: the lesions depend on estrogen to survive, and they make estrogen on the spot; estrogen drives pain- and inflammation-producing prostaglandins, and the prostaglandins push the lesion to make more estrogen, a loop that amplifies itself. At the same time, the lesions respond poorly to progesterone, which is supposed to be estrogen's brake, so the brake fails.
Still uncertain: the cause. Retrograde menstruation, blood flowing backward into the pelvis during a period, is the classic explanation, but about 90% of women have some backflow and only about 10% develop the disease, so backflow alone cannot explain whose cells survive.
Mechanism · How lesions make their own estrogen
Misplaced lesions depend heavily on estrogen to survive and grow. More strikingly, they make estrogen on the spot: endometriotic tissue abnormally expresses aromatase, the enzyme that converts androgens into estrogen, so a lesion does not rely only on what the ovaries release; it cooks its own supply (Bulun 2019).Estrogen stimulates an enzyme called COX-2, which produces prostaglandin (PGE2, a molecule that drives pain and inflammation); PGE2 in turn pushes aromatase higher, making yet more estrogen. This is a self-amplifying positive feedback loop in which estrogen and inflammation push each other up, and it helps explain why lesions become more stubborn and more painful the longer they persist. This chain has been worked out mainly in studies of lesion tissue and cells.
At the same time, the lesions respond poorly to progesterone, which is called progesterone resistance; progesterone is supposed to be estrogen's brake, and with the brake failing, the overgrowth is not held back. Treatment targets exactly this chain, rather than asking people to endure the pain; how it does so is covered in Why treatment targets estrogen.
Mechanism · What is still unknown about the cause
The classic explanation is the retrograde-menstruation theory Sampson proposed in 1927: during a period, some menstrual blood carrying cells from the uterine lining flows backward through the fallopian tubes into the pelvis, where the cells settle, survive and grow (Zondervan 2020).But the theory cannot explain everything on its own: about 90% of women have some degree of retrograde menstruation, yet only about 10% develop endometriosis. So something else must decide whose refluxed cells survive. There are several candidate explanations:
Failed immune clearance: normally, the immune system in the pelvis clears away refluxed cellsCoelomic metaplasia: cells native to the pelvis turn into lining-like tissue in response to certain signalsSpread through stem cells, the lymph or the blood: used to explain the rare lesions found far away, such as in the lungs or the noseGenetics plus epigenetics: it runs in families, and first-degree relatives have a higher risk
What is certain should be called certain, and what is not should be called uncertain. That the cause is not fully worked out does not make the disease any less real, and it does not mean you should just put up with it: the estrogen-and-inflammation chain is solid.
Chapter 3
Late diagnosis and what it costs
A period painful enough to disrupt your life is not a normal period.
Girls, parents and even doctors tend to treat very painful periods as normal. The symptoms are not specific, and no blood test can confirm the disease; imaging can show ovarian cysts and deep lesions but cannot see superficial lesions on the pelvic lining, so a clear ultrasound does not rule it out. The WHO fact sheet says the average time from first symptoms to diagnosis is 4-12 years.
This is not a diagnosis. Repeated severe period pain, pain that painkillers cannot control, or pain during sex or bowel movements are all reasons to see a gynecologist.
Girls, parents and even doctors tend to treat very painful periods as normal. The symptoms are not specific, and no blood test can confirm the disease; imaging can show ovarian cysts and deep lesions but cannot see superficial lesions on the pelvic lining, so a clear ultrasound does not rule it out. The WHO fact sheet says the average time from first symptoms to diagnosis is 4-12 years.
This is not a diagnosis. Repeated severe period pain, pain that painkillers cannot control, or pain during sex or bowel movements are all reasons to see a gynecologist.
Clinical · Why diagnosis takes years
From the first symptoms to diagnosis, the WHO fact sheet gives an average of 4-12 years (WHO 2023). It varies a great deal between countries, but a delay measured in years is the norm. In the Nnoaham 2011 ten-country study, the average was 6.7 years, mostly lost in primary care. Do not memorize any single figure as a worldwide average.Why does it take so long? Period pain is assumed to be normal, and "just put up with it" delays seeking help. The symptoms are not specific: pelvic pain, bloating, painful bowel movements and fatigue are easily taken for irritable bowel syndrome, ordinary cramps or stress. There is no simple blood test. Imaging (transvaginal ultrasound, MRI) can show ovarian endometriomas and deep lesions but cannot see superficial lesions on the pelvic lining. For a long time laparoscopic surgery was treated as the only gold standard for diagnosis, which also pushed diagnosis later; that has since changed, as described in Why treatment targets estrogen.
Background · What those years of delay cost
The real cost of those years of delay starts with pain: period pain that keeps getting worse, chronic pelvic pain, pain during sex, pain when passing stool or urine; many describe feeling hollowed out again every month. Endometriosis is also one of the major causes of infertility; an estimated 35-50% of women with endometriosis experience pain, infertility, or both (Zondervan 2020).Nnoaham 2011 was a cross-sectional study across multiple centers in ten countries, enrolling women having laparoscopy because of symptoms or for sterilization. Women found to have endometriosis had clearly lower physical quality of life than women with similar symptoms but no endometriosis, and each lost an average of about 10.8 hours of work a week, mostly through reduced effectiveness while at work. Chronic pain is also linked to higher risk of depression and anxiety. Being told you are too delicate, you are overthinking it is itself a second injury.
Repeated severe period pain that painkillers cannot control, pain during sex or bowel movements, or a year of trying to conceive without success: any one of these is worth a visit to a gynecologist, rather than enduring another year. Being taken seriously sooner means paying less of that cost. This is still not a diagnosis.
Chapter 4
Why treatment targets estrogen
The lesions depend on estrogen to survive, which is why proper treatment works: it lowers the estrogen the lesions are exposed to, so they shrink and the inflammation settles.
Painkillers only suppress symptoms and do not change the course of the disease; hormonal treatment and surgery act on the chain itself. Endometriosis cannot currently be cured, but it can be managed: controlling pain, protecting fertility and improving quality of life. Diagnosis has improved too, and treatment no longer has to wait for surgery. All of this belongs to your doctor, not to a medicine list found online.
Painkillers only suppress symptoms and do not change the course of the disease; hormonal treatment and surgery act on the chain itself. Endometriosis cannot currently be cured, but it can be managed: controlling pain, protecting fertility and improving quality of life. Diagnosis has improved too, and treatment no longer has to wait for surgery. All of this belongs to your doctor, not to a medicine list found online.
Clinical · How drugs cut the estrogen lesions see
Almost every drug treatment for endometriosis comes down to reducing the estrogen the lesions are exposed to (Bulun 2019; ESHRE 2022).Pain relief (for symptoms, as a first step): non-steroidal anti-inflammatory drugs () ease pain by acting on the prostaglandin link. They are a common first step, but they only suppress symptoms and do not change the course of the disease.
First-line hormonal treatment: progestogen alone (oral dienogest, a levonorgestrel-releasing intrauterine device or LNG-IUD, and others) or the combined oral contraceptive pill (COC). By suppressing ovulation and thinning the lining and the lesions, they lower circulating estrogen, so the lesions shrink and inflammation falls. ESHRE lists progestogens as a common first choice (inexpensive, well tolerated).
Second line: agonists or antagonists of gonadotropin-releasing hormone (GnRH), such as elagolix, relugolix and linzagolix, turn down ovarian estrogen more strongly, usually with a small amount of hormone added back (add-back therapy) to protect and reduce hot flashes. Aromatase inhibitors block the step in which the lesion makes its own estrogen and are used for hard-to-treat cases.
About one-third of patients respond poorly to progestogens (progesterone resistance) and need a different regimen, which is why treatment has to be individualized and followed up. This is a map of mechanisms, not a prescription.
Clinical · Surgery, and how diagnosis has changed
Surgery: removing or destroying lesions by laparoscopy can relieve pain, deal with ovarian endometriomas and improve some cases of infertility; but recurrence is common, and surgery is not a once-and-done fix.Diagnosis has improved too (ESHRE 2022): laparoscopy is no longer treated as the only gold standard. Typical symptoms combined with imaging (transvaginal ultrasound or MRI) can support a clinical diagnosis, and hormonal treatment can even be started on that basis to see how the symptoms respond, without waiting for surgery. This directly shortens the time to diagnosis.
Endometriosis cannot currently be cured, but it can be managed well. The aim of treatment is not to root it out but to control pain, protect fertility, stop it progressing and improve quality of life. All of this belongs to your doctor, and it also marks the limit of what nutrition can add, covered in What diet evidence shows.
Chapter 5
What diet evidence shows
Can food cure endometriosis? The honest answer has three layers.
First: the types of fat in the diet are associated with whether you get diagnosed with endometriosis, which is not the same as whether it can be treated once you have it. Second: anti-inflammatory or Mediterranean-style eating has early but very weak human evidence, and one often-cited study is not even a controlled trial. Third, and most important: major guidelines currently recommend no specific diet as a treatment.
So diet is an adjunct, not a substitute: it may help you feel a bit better and be healthier overall, but it cannot make the lesions disappear.
First: the types of fat in the diet are associated with whether you get diagnosed with endometriosis, which is not the same as whether it can be treated once you have it. Second: anti-inflammatory or Mediterranean-style eating has early but very weak human evidence, and one often-cited study is not even a controlled trial. Third, and most important: major guidelines currently recommend no specific diet as a treatment.
So diet is an adjunct, not a substitute: it may help you feel a bit better and be healthier overall, but it cannot make the lesions disappear.
Evidence · Diet and the risk of getting it
Omega-3 ( and from oily fish): a large prospective cohort study, Missmer 2010 (Nurses' Health Study II, more than 70,000 women followed for 12 years, 1,199 cases confirmed by laparoscopy), found that women in the highest fifth of long-chain omega-3 intake were about 22% less likely to be diagnosed with endometriosis than those in the lowest fifth, while those in the highest fifth of trans-fat intake were about 48% more likely. On mechanism this makes sense: omega-3 shifts prostaglandins toward the anti-inflammatory side, and trans fat does the opposite.Note carefully: this is an observed association with whether you get the disease, not evidence about whether it can be treated once you have it, and the two must not be confused. Online copy that turns this cohort into a food cure is mistaking a risk study for a treatment trial.
Evidence · Can diet treat it, and what guidelines say
A systematic review (Nirgianakis 2022) pooled 9 human studies and 12 animal studies. One of them, Ott 2012, was a before-and-after comparison with no control group (n=68, a Mediterranean-style diet for 5 months) that saw pain scores fall; the review's actual were not Mediterranean-diet trials. Overall the studies were few, at moderate to high risk of bias, and inconsistent. A reasonable reading is that a Mediterranean or anti-inflammatory eating pattern (more fish, olive oil, fruit and vegetables, whole grains and legumes; less trans fat and highly processed food) may help a little by lowering overall inflammation and influencing estrogen metabolism. The direction makes sense, but the evidence is not strong enough to turn it into a prescription you must follow.The third layer is the most honest one: the ESHRE 2022 guideline states that for non-drug interventions such as nutrition, exercise, acupuncture and physiotherapy, the evidence is insufficient and no recommendation can be made. That does not mean they certainly do not work; it means there is not yet enough high-quality evidence that they reduce pain or treat the disease. Diet is an adjunct, not a substitute: it may make you somewhat more comfortable and healthier overall, but it cannot make misplaced lesions disappear, and it cannot replace hormonal treatment or surgery.
Claims to be wary of: online promises that food can cure endometriosis, that cutting gluten and dairy reverses it, or that some detox plan clears the lesions all go far beyond the evidence. Extreme food restriction can also lead to poor nutrition and anxiety around eating, which is not worth the trade.
Chapter 6
Self-care and when to see a doctor
Diet cannot replace diagnosis, hormonal treatment or surgery. If you suspect endometriosis or have long-standing pelvic pain, take it to a gynecologist; nutrition and lifestyle are a valuable adjunct, but an adjunct, not a cure.
What you can do now: shift your diet in an anti-inflammatory direction, avoid extreme food restriction, use heat, and keep a pain diary. Period pain that keeps getting worse or that painkillers cannot control, chronic pelvic pain, pain during sex or bowel movements, and a year of trying to conceive without success are all reasons to see a gynecologist; sudden severe abdominal pain, heavy bleeding with dizziness or a racing heart, or abdominal pain or bleeding during pregnancy need medical care the same day.
Disclaimer: this page is health education, not a diagnosis or prescription; decide on medication, surgery and fertility with your gynecologist or fertility specialist.
What you can do now: shift your diet in an anti-inflammatory direction, avoid extreme food restriction, use heat, and keep a pain diary. Period pain that keeps getting worse or that painkillers cannot control, chronic pelvic pain, pain during sex or bowel movements, and a year of trying to conceive without success are all reasons to see a gynecologist; sudden severe abdominal pain, heavy bleeding with dizziness or a racing heart, or abdominal pain or bleeding during pregnancy need medical care the same day.
Disclaimer: this page is health education, not a diagnosis or prescription; decide on medication, surgery and fertility with your gynecologist or fertility specialist.
In practice · Low-risk things you can do yourself
Things you can do now (as an adjunct, low risk):Shift your diet toward an anti-inflammatory, Mediterranean-style pattern: oily fish 2-3 times a week (salmon, sardines), or an omega-3 supplement as needed; plenty of fruit and vegetables, whole grains, legumes and olive oil; and actively cut back on trans fat and highly processed food. Treat it as a long-term healthy habit with a possible small, gentle benefit, not as a therapy.
Avoid extreme food restriction: unless you have a clear personal intolerance (for example, if you also have irritable bowel syndrome), there is no need to cut out gluten or dairy on a hunch; the evidence is insufficient, and it can unbalance your nutrition.
Non-drug help for pain: heat on the lower abdomen (40-44 °C) eases period pain, and in one randomized trial a low-heat patch relieved pain as well as ibuprofen (see Menstrual Cycle); regular exercise and omega-3 also help period pain somewhat (Rahbar 2012). Both pieces of evidence come from primary dysmenorrhea, ordinary period pain, not from treatment trials in endometriosis.
Keep a record: use a period and pain diary to note when the pain comes, how strong it is (0-10), whether there is pain during sex or bowel movements, how heavy the bleeding is, and how many days of life it disrupted. This is the strongest material you can bring to a gynecologist.
Mental health and support: chronic pain combined with repeatedly being dismissed can easily lead to depression and anxiety; seeking psychological support is reasonable, not an overreaction.
Red flag · When to see a gynecologist, when to go now
Things that must go to a doctor (diet cannot solve): the diagnosis, hormonal therapy, surgery, and fertility planning of endometriosis all belong to gynecology / reproductive medicine — diet cannot replace them. See a gynecologist proactively — do not drag it out another year — if any of these apply: progressively worsening dysmenorrhea, unrelieved by painkillers, disrupting work or school; chronic pelvic pain (still painful after menses ends); painful sex, defecation, or urination; markedly heavier flow or disordered cycles; a year of trying to conceive (six months if over 35) without success.ER red flags: sudden severe abdominal pain (beware ruptured / torsed ovarian endometrioma), heavy bleeding with dizziness or palpitations, abdominal pain or bleeding in pregnancy — seek care the same day.
Endometriosis is a real, estrogen-driven chronic inflammatory disease; its cause is not fully worked out, but its mechanism and treatment are clear. Nutrition and lifestyle are a valuable adjunct, but an adjunct, not a cure. If you suspect endometriosis, or have long-standing pelvic pain, take it to a gynecologist; being taken seriously sooner spares you years of needless pain.
Related topics: how period pain relates to prostaglandins is covered in the story on the menstrual cycle (see Menstrual Cycle); people with heavy periods should also watch for iron deficiency; and fish oil and omega-3 in inflammation, as well as the estrogen changes of perimenopause, each have their own stories on the site.
References · 9
- World Health Organization. (2023). Endometriosis [Fact sheet]. Geneva: WHO. www.who.int/news-room/fact-sheets/detail/endometriosis
- Zondervan, K. T., Becker, C. M., & Missmer, S. A. (2020). Endometriosis. New England Journal of Medicine, 382(13), 1244-1256. 10.1056/NEJMra1810764
- Critchley, H. O. D., Babayev, E., Bulun, S. E., Clark, S., Garcia-Grau, I., Gregersen, P. K., et al. (2020). Menstruation: science and society. American Journal of Obstetrics & Gynecology, 223(5), 624-664. 10.1016/j.ajog.2020.06.004
- Bulun, S. E., Yilmaz, B. D., Sison, C., Miyazaki, K., Bernardi, L., Liu, S., et al. (2019). Endometriosis. Endocrine Reviews, 40(4), 1048-1079. Pelvic endometriosis is characterised by an estrogen-dependent chronic inflammatory process; excess local estrogen production drives inflammation through estrogen receptor-β, and progesterone receptor deficiency causes progesterone resistance. Pain is managed by suppressing ovulatory menses and estrogen production, cyclooxygenase inhibitors and surgery (abstract, PMID 30994890). 10.1210/er.2018-00242
- Nnoaham, K. E., Hummelshoj, L., Webster, P., d'Hooghe, T., de Cicco Nardone, F., de Cicco Nardone, C., et al. (2011). Impact of endometriosis on quality of life and work productivity: a multicenter study across ten countries. Fertility and Sterility, 96(2), 366-373.e8. Cross-sectional, ten countries: mean delay of 6.7 years from symptom onset to surgical diagnosis, mostly in primary care. 10.1016/j.fertnstert.2011.05.090
- Becker, C. M., Bokor, A., Heikinheimo, O., Horne, A., Jansen, F., Kiesel, L., et al.; ESHRE Endometriosis Guideline Development Group. (2022). ESHRE guideline: endometriosis. Human Reproduction Open, 2022(2), hoac009. 10.1093/hropen/hoac009
- Missmer, S. A., Chavarro, J. E., Malspeis, S., Bertone-Johnson, E. R., Hornstein, M. D., Spiegelman, D., et al. (2010). A prospective study of dietary fat consumption and endometriosis risk. Human Reproduction, 25(6), 1528-1535. 10.1093/humrep/deq044
- Nirgianakis, K., Egger, K., Kalaitzopoulos, D. R., Lanz, S., Bally, L., & Mueller, M. D. (2022). Effectiveness of dietary interventions in the treatment of endometriosis: a systematic review. Reproductive Sciences, 29(1), 26-42. 10.1007/s43032-020-00418-w
- Rahbar, N., Asgharzadeh, N., & Ghorbani, R. (2012). Effect of omega-3 fatty acids on intensity of primary dysmenorrhea. International Journal of Gynaecology and Obstetrics, 117(1), 45-47. 10.1016/j.ijgo.2011.11.019