Endometriosis may be a whole-body disease, not just a pelvic one

Endometriosis has long been treated as a disease confined to the pelvis, managed largely by gynaecologists. Yet women who live with it often describe a far wider pattern of trouble, from joint pain and gut problems to allergies and exhaustion. If those comorbidities cluster with endometriosis more often than chance would predict, the traditional definition starts to look too narrow, and the way the condition is diagnosed and managed would need rethinking. This review set out to measure, across the whole published literature, whether endometriosis genuinely travels with autoimmune diseases, allergic conditions, chronic pain syndromes and endocrine disorders.

The authors searched two major databases from their inception to the end of December 2025, plus the reference lists of identified papers, for observational studies reporting quantitative links between endometriosis and a predefined set of comorbidities in women. Fifty-five studies met the inclusion criteria and 48 provided enough data for quantitative pooling. Of these, 32 examined autoimmune diseases including lupus, Sjögren's syndrome, rheumatoid arthritis, multiple sclerosis, coeliac disease and inflammatory bowel disease, while 17 covered allergic diseases, 13 covered pain syndromes and 6 covered endocrine disorders. The quality of the evidence was assessed using the GRADE framework.

Women with endometriosis showed significantly higher risks of several autoimmune diseases, including lupus, Sjögren's syndrome and rheumatoid arthritis in studies that followed women over time, with other study designs also pointing to multiple sclerosis and coeliac disease. Allergic conditions were more common too, including asthma and eczema, as were pain syndromes such as fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome. Not everything was elevated: the odds of hypothyroidism and hyperthyroidism showed no statistically significant increase. Crucially, the overall quality of the evidence was rated low or very low, largely because most of the underlying studies carried a high risk of bias.

The findings support a growing push to reframe endometriosis as a systemic immuno-inflammatory disorder rather than a local pelvic disease, a shift the authors argue is underpinned by shared immune dysregulation and central sensitisation. Because all the included studies followed people rather than testing interventions, the direction of these relationships remains unproven: shared underlying causes, diagnostic overlap and the fact that women under medical care are more likely to receive other diagnoses could all inflate the associations. The key open questions are whether treating the inflammatory biology changes the comorbidities, and which women are most at risk of developing them.

For a woman with endometriosis, this is a reason to see symptoms beyond the pelvis as potentially connected rather than coincidental, and to raise the diagnosis when other conditions are being investigated. It is not a prediction that any individual will develop an autoimmune disease: these are associations drawn from low-quality evidence, and most women with endometriosis will not develop the conditions studied. The broader significance lies in how care is organised, with the authors calling for a patient-centred, multidisciplinary approach rather than a purely gynaecological one.