Is MCAS connected to endometriosis?

Yes—there appears to be an evolving connection, but it’s not as simple as “endometriosis equals MCAS.” What current research supports most strongly is that mast cells (the immune cells involved in allergic-type reactions) are often increased and more activated in and around endometriosis lesions, where they tend to cluster near nerves and blood vessels. When mast cells release mediators like histamine and other inflammatory signals, they can irritate pain-sensing nerves, promote nerve growth, and help sustain inflammation—one plausible reason endometriosis pain can feel burning, stabbing, widespread, or unusually persistent.

MCAS, though, is a systemic syndrome—meaning it can cause multi-system flares (for example flushing/itching, GI upset, shortness of breath, dizziness or fast heart rate) and may be triggered by stress, hormones, foods, or environmental exposures. Some people with endometriosis also have MCAS-like symptoms, and in those cases mast-cell biology may be amplifying pelvic pain and lowering the threshold for flares across the body. If this overlap sounds familiar, our team can help you sort out what’s likely being driven by endometriosis lesions themselves (including whether excision surgery may be part of your plan) versus broader mast-cell–type sensitivity that may need coordinated perioperative and long-term management.