Endometriosis is one of the most common and, at the same time, least publicly understood gynaecological conditions. According to the WHO, it affects around 10% of women of reproductive age — approximately 190 million people worldwide. Yet the average time from the onset of symptoms to a confirmed diagnosis is seven to ten years. This is not accidental: the symptoms of endometriosis are easy to mistake for 'heavy periods', and diagnosis requires surgical confirmation. What actually happens in endometriosis? Cells resembling the endometrium — the inner lining of the uterus — are found outside the uterus, on the ovaries, fallopian tubes, peritoneum, bowel and bladder. Like normal endometrial tissue, these lesions respond to hormonal changes across the cycle: they grow, and they bleed at menstruation — but the blood has nowhere to go. This causes inflammation, scarring and adhesions.
Painful periods (dysmenorrhoea) — the most common symptom. The crucial distinction: this is not ordinary discomfort, but pain severe enough to interfere with daily functioning and unresponsive to standard painkillers. Many women spend years accepting such pain as normal — 'my body is just like that'. It is not normal. Chronic pelvic pain — pain unrelated to menstruation, present continuously or cyclically. It may radiate to the lower back or legs. Painful sex (dyspareunia) — particularly with deep penetration. This reflects involvement of the pouch of Douglas or the uterosacral ligaments. One of the symptoms most rarely mentioned to a doctor — out of embarrassment or the sense that 'it must be normal'. Bowel and bladder problems during menstruation. Painful defecation, diarrhoea, constipation, urinary frequency or pain — all of these can be symptoms of endometriosis when the relevant organs are affected. Infertility. Around 30 to 50% of women with endometriosis experience difficulty conceiving. For many, this is the first reason they seek medical attention — and the diagnosis is made in the course of a fertility workup. Important: the severity of symptoms does not correlate with the stage of disease. A woman with stage IV endometriosis (the most severe) may have moderate symptoms, while a woman with stage I may have debilitating pain. This is one of the reasons the condition is so difficult to diagnose from clinical presentation alone.
A fundamental problem: endometriosis cannot be diagnosed from symptoms alone or from ultrasound. Ultrasound can detect ovarian endometriomas (cysts filled with old blood) but cannot see superficial peritoneal lesions. The gold standard for diagnosis is laparoscopy with histological confirmation. This is a minimally invasive surgical procedure in which the surgeon visually examines the pelvic organs and takes tissue samples for analysis. This is the only way to reliably establish and stage the diagnosis. This means that every diagnosis of endometriosis involves a surgical procedure. This is precisely why diagnosis so often comes late: many gynaecologists prefer to prescribe hormonal treatment empirically first, reserving surgery for when treatment fails or complications are suspected. The biomarker CA-125 is sometimes mentioned in the context of endometriosis — but its diagnostic value is limited. It may be elevated in endometriosis but also in other conditions; a normal level does not exclude the disease.
How exactly does endometriosis reduce fertility? There are several mechanisms, not all equally well understood. Mechanical effects: adhesions and scar tissue can distort the anatomy of the fallopian tubes and ovaries — physically blocking the path of the egg or sperm. Ovarian endometriomas take up space and can damage healthy ovarian tissue, reducing ovarian reserve. Inflammatory environment: in endometriosis, peritoneal fluid contains elevated levels of inflammatory cytokines, prostaglandins and activated macrophages. This environment is toxic to sperm and embryos. Research shows that even minimal endometriosis (stages I--II) without visible structural changes is associated with lower conception rates than in healthy women. Impaired implantation: endometriosis appears to affect endometrial receptivity to implantation — though the mechanisms are still being studied. This explains why some women with endometriosis cannot conceive even in the absence of visible structural abnormalities. Reduced ovarian reserve: surgery on the ovaries for endometriomas carries a risk of damaging healthy ovarian tissue. The decision to operate must always be weighed against the impact on ovarian reserve — particularly when pregnancy is planned.
Hormonal therapy (contraceptive pills, progestins, GnRH agonists) suppresses lesion activity and relieves symptoms — but does not eliminate the disease and does not directly improve fertility. While on hormonal therapy, conception is not possible. Surgical treatment (laparoscopy) removes or destroys endometriotic lesions. This can improve symptoms and — in some cases — increase the likelihood of spontaneous conception. However, in moderate to severe endometriosis with reduced ovarian reserve, the benefit of surgery before IVF is not clear-cut: some studies show no improvement in IVF outcomes following surgery, while the risk of reducing reserve is real. IVF is an effective treatment for infertility associated with endometriosis. It bypasses several of the mechanisms that impair fertility — the inflammatory environment and adhesions — and ensures fertilisation and early embryo development under controlled laboratory conditions. In severe endometriosis, IVF is often the first-line treatment.
Endometriosis is a chronic condition requiring long-term management, not a one-time cure. It does not 'resolve' after surgery: recurrence is possible. It does not always prevent pregnancy — many women with endometriosis conceive naturally. But it significantly increases the risk of difficulty conceiving — which is precisely why early diagnosis matters. If you have painful periods, chronic pelvic pain or difficulty conceiving — these are sufficient reasons to consult a specialist. Years of tolerating pain as 'a female thing' are not necessary.
Join thousands building families on their own terms.
Browse Profiles