Women diagnosed with endometriosis face more than double the odds of also suffering from migraines, according to a sweeping new analysis covering more than 13 million patient records.
Quick Take
- A review of 35 studies covering more than 13 million women found those with endometriosis had 2.3 times the odds of migraine.
- A separately published 2025 peer-reviewed study of 331,655 people found a nearly identical risk increase.
- An earlier 2020 study found a smaller, but still real, link between the two conditions.
- Researchers point to shared inflammation and nerve pathways as a likely explanation, though the exact cause remains unproven.
A Massive Data Set Points to a Real Connection
The headline figure comes from an analysis presented at the American Neurological Association Annual Meeting. It pooled data from 35 studies spanning roughly 50 years, covering 13,170,795 women total, including 207,675 with endometriosis. Women with the condition had 2.3 times the odds of also having migraines, with a confidence range of 1.75 to 3.05, a gap wide enough to confirm the link is real but not precise enough to pin down the exact size.
Endometriosis affects tissue that normally lines the uterus, except it grows outside it, causing chronic pelvic pain, heavy periods, and sometimes infertility. Migraines bring intense, often one-sided headaches paired with nausea and sensitivity to light. Both conditions disproportionately affect women during their reproductive years, and both have long been difficult for doctors to diagnose quickly, which is part of why researchers suspect they may share more than just a calendar overlap.
Peer-Reviewed Research Backs the Same Direction
This is not a one-off finding. A 2025 systematic review and meta-analysis, published in the Journal of Headache and Pain, reviewed 13 studies involving 331,655 people and found an odds ratio of 2.25, with a confidence interval of 1.85 to 2.72. That number lines up closely with the newer 2.3 estimate, even though the two analyses used different study pools and methods.
A smaller 2020 meta-analysis had already flagged the connection, reporting an odds ratio of 1.56 with a confidence interval of 1.21 to 1.90. The lower number likely reflects fewer included studies and stricter inclusion criteria at the time. Together, three separate analyses spanning five years now point the same direction: endometriosis and migraine show up together far more often than chance would predict.
Why Diagnosis Delays Could Shape the Numbers
Endometriosis is notoriously slow to diagnose, often taking six to ten years from first symptoms to a confirmed diagnosis. During that stretch, women typically rack up more doctor visits, emergency room trips, and specialist referrals than women without the condition. That higher contact with the healthcare system means doctors have more chances to also notice and record migraines, which could inflate how strong the measured link appears.
Researchers behind the 2025 review noted that few of the included studies adjusted for confounding factors like hormonal birth control use, obesity, or other chronic pain conditions, which limits how firmly the link can be explained by biology alone. The leading theory ties both conditions to overlapping inflammatory responses and shared nerve signaling pathways in the body, but that explanation still needs direct testing before it can be called proven.
For now, the takeaway is straightforward. Women managing endometriosis who also battle frequent migraines are not imagining a coincidence. Multiple large studies, using different methods and different time periods, keep finding the same pattern. What remains unsettled is exactly why, and untangling that will likely take years of further research into shared biology, diagnosis timing, and treatment effects.
Sources:
mindbodygreen.com, link.springer.com, acnr.co.uk, headachemedicine.com.br, tandfonline.com, healthline.com
