Your joints have always been unusually flexible. You were the kid who could bend your thumb to your wrist. Standing too long makes your heart race and your vision gray out. And somewhere along the way, you started reacting to foods, heat, and fragrances.
Each problem might have been noticed by a different doctor. Few people are told they could be connected.
The three conditions
- Hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders involve unusually flexible joints, often with joint instability, pain, easy bruising, and soft or stretchy skin. hEDS is diagnosed using 2017 clinical criteria. Unlike some other forms of EDS, there is currently no genetic test for it.
- Postural orthostatic tachycardia syndrome (POTS) is a form of autonomic dysfunction. The heart rate rises sharply on standing, with lightheadedness, fatigue, and brain fog.
- Mast cell activation syndrome (MCAS) involves mast cells releasing inflammatory mediators too easily, causing symptoms across the skin, gut, heart, airways, and nervous system.
What research says about the overlap
Clinicians who see these conditions have reported for years that they cluster in the same patients. A 2020 review in Clinical Reviews in Allergy & Immunology (Kohn and Chang) examined the relationship among hEDS, POTS, and MCAS and described substantial overlap in clinical populations.
Genetics may play a part for some people. Hereditary alpha-tryptasemia, a common trait that raises baseline tryptase, has been associated in research (Lyons et al., 2016) with symptoms including joint hypermobility, dysautonomia, and mast cell–type complaints.
What isn’t established: there’s no proven single mechanism linking all three. Much of the evidence comes from specialty clinic populations, which can overstate how often conditions occur together. Having one doesn’t mean you have the others.
Why the connection matters in practice
These conditions can amplify each other:
- Mast cell mediators can affect blood vessel tone, which may worsen symptoms on standing.
- Heat, a common mast cell trigger, also worsens orthostatic intolerance.
- Flares in one area can make the whole picture feel worse.
When each is evaluated in isolation, patients are often told individual findings are mild. The combined effect on daily life isn’t mild.
Signs the three may be connected in your case
- Lifelong joint flexibility, frequent sprains, or joints that slip or sublux
- Racing heart, dizziness, or near-fainting when standing
- Flushing, hives, or itching with heat, friction, or certain foods
- GI symptoms that don’t fit a single diagnosis
- Symptoms that worsen together during illness, heat, or stress
How it is evaluated
- Joint hypermobility assessment and history, including family history.
- Orthostatic vital signs: heart rate and blood pressure lying down and standing.
- A mast cell symptom and trigger history, with timed mediator testing where appropriate.
- Baseline tryptase review, which can raise the question of hereditary alpha-tryptasemia.
- Coordination with cardiology, genetics, rheumatology, or allergy and immunology as needed.
When to get emergency care
Call 911 for:
- fainting with injury,
- chest pain,
- throat swelling or trouble breathing, or
- a joint dislocation with numbness or loss of circulation.
Serving Oklahoma City, Tulsa, and all of Oklahoma
Venturis Clinic sees patients from Oklahoma City and surrounding areas, including Tulsa, and from across Oklahoma. Learn more on our MCAS in Oklahoma City page.
Frequently asked questions
Are hEDS, POTS, and MCAS the same condition? No. They’re distinct conditions that are frequently reported together.
If I have hEDS, will I get MCAS? Not necessarily. Many people with hypermobility never develop mast cell or autonomic symptoms.
Is there a test for hEDS? There’s no genetic test for hEDS. It’s diagnosed with clinical criteria, and other forms of EDS may need genetic testing to be ruled out.
What is hereditary alpha-tryptasemia? A common inherited trait that raises baseline tryptase. It has been associated with multisystem symptoms in some people.
Tired of having three problems treated as unrelated? Book a free 15-minute discovery call, or learn more about MCAS care in Oklahoma City.
This page is for educational purposes and is not a substitute for individual evaluation.
By Alvin Philipose, DC, ICCP
Sources
- Kohn A, Chang C. The relationship between hypermobile Ehlers-Danlos syndrome (hEDS), postural orthostatic tachycardia syndrome (POTS), and mast cell activation syndrome (MCAS). Clinical Reviews in Allergy & Immunology. 2020;58(3):273–297.
- Lyons JJ, et al. Nature Genetics. 2016;48(12):1564–1569.
- Malfait F, et al. The 2017 international classification of the Ehlers-Danlos syndromes. American Journal of Medical Genetics Part C. 2017;175(1):8–26.