A major genetics study has found dozens of new signals linked to endometriosis, offering fresh insight into the biology driving the condition.

Endometriosis is a systemic disease affecting around 10 per cent of females worldwide.

It happens when tissue similar to the lining of the uterus grows outside it, causing pain, inflammation and fertility problems.

Despite how common it is, the underlying causes have remained poorly understood, slowing progress in diagnosis and treatment.

In one of the largest investigations to date, researchers analysed genetic data from approximately 1.4 million females, including more than 105,000 with endometriosis.

The study identified 80 genomic regions linked to disease risk, including 37 previously unreported loci, or specific positions on chromosomes, significantly advancing understanding of endometriosis genetics.

Notably, five of these regions were also linked to adenomyosis, a related condition in which endometrial-like tissue grows within the wall of the uterus.

Beyond identifying genetic variants, the researchers integrated transcriptomic, epigenetic and proteomic data, which examine gene activity, chemical changes regulating genes and proteins, to better understand how these variants influence disease development.

This multi-omics approach linked endometriosis genetics to key biological processes, including cell differentiation, immune response, hormonal regulation, tissue remodelling and inflammation.

These findings support long-standing hypotheses that endometriosis is not solely a localised gynaecological condition but a complex, systemic disorder involving immune and hormonal dysregulation.

The study also found that genetic risk for endometriosis interacted with a range of clinical symptoms, including abdominal pain, anxiety, migraine and nausea.

This reinforces the multifaceted nature of the disease and may help explain why patients often experience a broad spectrum of symptoms beyond pelvic pain.

Such insights could improve patient stratification in the future, enabling more personalised approaches to management based on genetic risk profiles.

The analysis also identified potential therapeutic targets through drug-repurposing approaches.

Some of the implicated pathways overlap with those targeted by existing treatments for breast cancer, contraception and preterm birth prevention, raising the possibility of accelerating new treatment strategies for endometriosis.

Women have described being dismissed and left in serious pain during routine hysteroscopy examinations, with many given little or no pain relief.

Users of parenting forum Mumsnet who underwent hysteroscopy procedures also shared concerns about receiving unclear information before treatment and being given little or no pain relief afterwards.

Some women, who described feeling physically and emotionally vulnerable, compared the experience to sexual assault.

Research led by the University of Reading analysed 4,644 posts from Mumsnet users written between 2018 and 2024.

Susanne Cromme, lead author from the University of Reading, said: “Women in their thousands say they are going into hysteroscopy procedures unprepared, left in more pain than they were led to expect, and feeling that their experience is not being taken seriously, our analysis shows.

“This is not simply an online pile-on. The themes we found in our research are consistent with what clinical studies already tell us about hysteroscopy.

“But by listening to women talk to each other openly, without a researcher in the room, we get a much richer picture of the issues facing patients.”

The study was published following the launch of the Mumsnet campaign to End Medical Misogyny, which is fighting to end the “systemic dismissal, disbelief or de-prioritisation of women’s symptoms in healthcare”, and comes after health secretary Wes Streeting said the health system “too often gaslights women, treating their pain as an inconvenience.”

Justine Roberts, founder of Mumsnet and Gransnet, said: “This research makes clear that too many women are still experiencing severe pain during hysteroscopy, and that problem is compounded by unclear information, inconsistent pain relief and a lack of proper consent.

“These are not one-off failures, they form a repeated pattern and that’s exactly what Mumsnet’s medical misogyny campaign is highlighting: systemic failings in women’s healthcare.

“Nothing encapsulates that more clearly than the expectation that women should endure avoidable pain during gynaecological procedures. If the NHS is serious about tackling medical misogyny, this has to change.”

Around 71,000 hysteroscopy procedures take place every year in England.

According to the analysed Mumsnet posts, women were told procedures would be no worse than a smear test, felt unable to stop once they had started and found that the pain relief available depended entirely on which NHS trust they attended.

The analysis identified five recurring problems among hysteroscopy patients: not enough information before the procedure; women feeling exposed and unprotected; a “postcode lottery” for pain relief, with wide variation between trusts; pain being played down by staff; and an unequal standard of care.

Women also questioned why sedation routinely offered for procedures such as colonoscopies and endoscopies, which examine the bowel and digestive tract, was not available for gynaecological procedures.

The researchers said the findings suggest the problems go beyond individual clinicians, as the posts reflect wider structural issues in women’s healthcare, including potentially underfunded services and unequal standards of care.

The study calls for NHS trusts to introduce standardised consent processes that give women clear information about pain, alternatives and what to expect.

It also recommends consistent pain management protocols across all hospitals, and training for clinicians in trauma-informed care.