Reframing endometriosis part 1
Endometriosis is a chronic gynaecological condition characterised by the presence of endometrial-like tissue outside the uterus1. Symptoms of endometriosis often include dysmenorrhea (painful menstruation), non-menstrual pelvic pain, and infertility1,2,3. Endometriosis affects 176 million women worldwide taking on average 8 years and 10 months from first doctor visit to diagnosis4.
Currently, the most widely accepted hypothesis for its origin is the retrograde menstruation, first proposed in 1927, which suggests that menstrual tissue flows backward through the fallopian tubes into the pelvic cavity, where it implants and grows3. However, this theory fails to explain why many women with retrograde menstruation do not develop the condition, nor does it account for cases where endometrium-like tissue has been found outside the pelvic region, which may be linked to dissemination via the lymphatic or circulatory systems5.
Furthermore, while some women with endometriosis remain asymptomatic, others experience debilitating symptoms, highlighting a spectrum of disease severity that remains poorly understood. The precise aetiology of endometriosis is still unclear, although abnormalities in immune function have been proposed as a contributing factor, with growing evidence suggesting a potential link between endometriosis and autoimmune disorders3. These complexities have prompted researchers, clinicians and others to ask: is endometriosis truly just a gynaecological disorder?
Association between endometriosis and autoimmune diseases – a genetic link
The link between endometriosis and autoimmune diseases has been proposed by numerous studies including Kvaskoff et al.,2014, Shigesi et al.,2019, Aziz et al., 20253,6,7. Current research recognises that endometriosis has a strong heritable component, prompting investigations into whether genes commonly associated with autoimmune conditions may also play a role in its development8. Building on this foundation, the most recent study by Shigesi et al., 2025 expands the scope by examining both clinical and genetic associations between endometriosis and a range of immune-mediated and inflammatory disorders, including osteoarthritis, rheumatoid arthritis, multiple sclerosis, coeliac disease, and psoriasis9. The study’s findings show that women with endometriosis face a 30–80% increased risk of developing autoimmune diseases, suggesting that a shared genetic basis may underlie this elevated risk9. Earlier research had already identified overlapping genetic markers in women with both rheumatoid arthritis and endometriosis8, but these studies were limited by small sample sizes and a lack of ethnic diversity. In contrast, the Shigesi et al., 2025 study brings confidence to the earlier findings by drawing on a robust dataset of over 8,000 endometriosis cases and 64,000 cases of immunological disease in the UK, offering greater translatability and insight into the biological mechanisms at play9.
This genetic overlap suggests that endometriosis may share biological pathways with autoimmune diseases, challenging the notion that it is solely a reproductive disorder. Rather than reinforcing a narrow classification, it opens the door to viewing endometriosis as a systemic condition, one shaped by immune dysfunction, chronic inflammation, and multisystem involvement. This evolving understanding opens new avenues for therapeutic interventions and improved monitoring of immunological conditions in women with endometriosis.
Should we reframe endometriosis?
Studies like Shigesi et al., 2025, challenge the long-standing classification of endometriosis as solely a gynaecological disorder9, asking us to reconsider its nomenclature. Although further evidence is needed to causally show that endometriosis can be classified as an autoimmune disease, genetic studies such as this offer a transformative opportunity for both clinical care and research.
Investigating genetic overlaps with autoimmune disorders like rheumatoid arthritis may reveal shared biological pathways and lead to the identification of biomarkers that predict disease severity, risk, or treatment response. These insights could pave the way for blood tests based on genetic and immune profiling, allowing for the early identification of individuals at risk, before symptoms become debilitating, significantly reducing diagnostic delays. Currently, diagnosis ranges from 7-10 years and relies heavily on laparoscopy, an invasive surgical procedure, with treatment typically centred on hormone-based therapies4. Broadening the definition would be a major step towards personalised medicine, potentially offering patients with alternative therapeutic approaches. If endometriosis shares mechanisms with autoimmune diseases, immunomodulatory treatments could offer relief for many patients, especially those who don’t respond to conventional therapies9. This broader perspective also encourages cross-disciplinary care, involving immunologists, pain specialists, and endocrinologists, not just gynaecologists.
Perhaps most importantly, this reframing validates the lived experiences of millions of women globally. Symptoms like fatigue, brain fog, and joint pain, often dismissed or overlooked, gain legitimacy when endometriosis is recognised beyond just a gynaecological disorder. This reframing gives women the language, and leverage to advocate for themselves, whether in clinical settings, workplace or other conversations, ensuring their experiences are recognised and their needs are met. This also shifts the narrative: endometriosis is not just “bad period pain.” It’s a complex, chronic condition that deserves the same attention, funding, and urgency as other immune-related diseases.
In the next article, Reframing endometriosis part 2, we’ll explore how immune cell dysfunction and hormonal-immune interactions drive endometriosis, and how this understanding could reshape public health policy, global care strategies, and long-term disease management.
References
- Farquhar, C. M. (2007). Endometriosis. BMJ, 334(7587), 249–253. https://doi.org/10.1136/bmj.39073.736829.be
- Ballard, K. D., Seaman, H. E., de Vries, C. S., & Wright, J. T. (2008). Can symptomatology help in the diagnosis of endometriosis? Findings from a national case–control study—Part 1. BJOG: An International Journal of Obstetrics and Gynaecology, 115(11), 1382–1391. https://doi.org/10.1111/j.1471-0528.2008.01878.x
- Shigesi, N., Kvaskoff, M., Kirtley, S., Feng, Q., Fang, H., Knight, J. C., Missmer, S. A., Rahmioglu, N., Zondervan, K. T., & Becker, C. M. (2019). The association between endometriosis and autoimmune diseases: A systematic review and meta-analysis. Human Reproduction Update, 25(4), 486–503. https://doi.org/10.1093/humupd/dmz014
- Endometriosis UK. (n.d.). Endometriosis facts and figures. https://www.endometriosis-uk.org/endometriosis-facts-and-figures
- Samani, E. N., Mamillapalli, R., Li, F., Mutlu, L., Hufnagel, D., Krikun, G., & Taylor, H. S. (2019). Micrometastasis of endometriosis to distant organs in a murine model. Oncotarget, 10, 2282–2291. https://doi.org/10.18632/oncotarget.16889
- Kvaskoff, M., Mu, F., Terry, K. L., Harris, H. R., Poole, E. M., Farland, L., & Missmer, S. A. (2015). Endometriosis: A high-risk population for major chronic diseases? Human Reproduction Update, 21(4), 500–516. https://doi.org/10.1093/humupd/dmv013
- Aziz, M., Beaton, M. A., Opoku-Anane, J., & Elhadad, N. (2025). Endometriosis and autoimmunity: A large-scale case-control study of endometriosis and 10 distinct autoimmune diseases. npj Women’s Health, 1, Article 6. https://doi.org/10.1038/s44294-025-00086-8
- Bianco, B., André, G. M., Vilarino, F. L., Peluso, C., Mafra, F. A., Christofolini, D. M., & Barbosa, C. P. (2012). The possible role of genetic variants in autoimmune-related genes in the development of endometriosis. Human Immunology, 73(3), 306–311. https://doi.org/10.1016/j.humimm.2011.12.009
- Shigesi, N., Harris, H. R., Fang, H., Ndungu, A., Lincoln, M. R., Cotsapas, C., Knight, J., Missmer, S. A., Morris, A. P., Becker, C. M., Rahmioglu, N., Zondervan, K. T., International Endometriosis Genome Consortium, & 23andMe Research Team. (2024). The phenotypic and genetic association between endometriosis and immunological diseases. Human Reproduction, 39(12), 2345-2358. https://doi.org/10.1093/humrep/deaf062 .
