EDS, POTS, and MCAS: How Hypermobility, Dizziness, and Mast Cell Symptoms Connect

Dr. Sasha Rose, ND said that more often than not she sees at least two of the three together in the same patient. Connective tissue affects joint stability and blood vessel support, dysautonomia affects heart rate, circulation, digestion, temperature regulation and energy, and mast cell activation affects immune and inflammatory signaling. She described the relationship as not linear, so it is not that one condition simply causes the next. Having one of them does not mean you have the other two.

No. Dr. Sasha Rose, ND described hypermobility as more than flexibility. She looks for a history of frequent sprains, joints that feel unstable or slip out, chronic pain, easy injury, balance that feels off, and connective tissue that feels stretchy or fragile, often with headaches, pelvic floor problems and fatigue. Colin Renaud, PA-C uses the Beighton score, a nine point screening tool, during a physical exam. He also said EDS itself is a specific genetic diagnosis that usually needs a geneticist to confirm, while hypermobility sits on a spectrum.

Colin Renaud, PA-C said basic labs do not capture joint instability, heart rate changes when you stand, mast cell chemical release, slow gut motility, or reactions to foods, smells and chemicals. Dr. Sasha Rose, ND put it plainly. Nobody is lying to you, the labs really are normal, they are just not measuring the underlying problem. She added that colonoscopies and endoscopies can look clean because much of this happens at a cellular level, and that the deeper functional testing they use is meant to go alongside standard screening, not replace it.

Colin Renaud, PA-C said both are mast cell disorders but they are distinct. Mastocytosis is an abnormal buildup of too many mast cells in tissues like the skin, bone marrow, GI tract and liver, and it is often linked to a specific genetic mutation. MCAS means you have a normal number of mast cells that are overreacting. He said mastocytosis is usually worked up by a hematologist oncologist using physical exam, skin or bone marrow biopsy, and a baseline elevated tryptase level.

Colin Renaud, PA-C said estrogen is very mast cell provoking, so he sees symptoms spike during puberty, menstrual cycles, pregnancy, breastfeeding and menopause. Dr. Sasha Rose, ND said those estrogen fluctuations, including postpartum and perimenopause, can set off histamine reactions or dysautonomia symptoms that were mild before. Both said most of their patients with these syndromes are women, and Colin Renaud, PA-C cited research estimating that about 75 to 80 percent of POTS patients are female. Dr. Rose also sees PCOS and endometriosis alongside these conditions, with inflammation as a shared factor.

Colin Renaud, PA-C was blunt about this. A clinician can be excellent at functional medicine and still know very little about MCAS, because many focus on hormones, gut health or nutrition. He said what matters is finding a provider who is literate in these conditions, whether that is a naturopath, an MD or a chiropractor with real experience, and in his view allergy immunology and gastroenterology often miss MCAS. Dr. Sasha Rose, ND added that a good provider also knows when to refer, using cardiology, GI or immunology to rule out other causes before settling on a pattern.