Understanding the Connection: Ehlers-Danlos, MCAS, and POTS

At Galene Health, many of our patients are diagnosed not only with POTS (Postural Orthostatic Tachycardia Syndrome), but also with conditions like Ehlers-Danlos Syndrome (EDS) and Mast Cell Activation Syndrome (MCAS). These three often overlap, and understanding why can help patients feel less alone — and more empowered in their care.

What is POTS?

POTS is a type of dysautonomia, meaning it involves a dysfunction of the autonomic nervous system. The hallmark sign is an excessive increase in heart rate when standing up, often accompanied by dizziness, fatigue, brain fog, and sometimes fainting.

What is Ehlers-Danlos Syndrome (EDS)?

EDS is a group of connective tissue disorders. The most common type seen in patients with POTS is hypermobile EDS (hEDS). In hEDS, the body’s connective tissues — which provide structure and support to joints, skin, and blood vessels — are looser and more fragile than usual.

• Common features: joint hypermobility (“double-jointed”), frequent sprains or injuries, soft or stretchy skin, and sometimes chronic pain.

• Why it matters in POTS: Weak connective tissue in blood vessel walls can make it harder for blood to move back up from the legs when standing. This may worsen the pooling of blood and contribute to POTS symptoms.

  
  

What is Mast Cell Activation Syndrome (MCAS)?

MCAS is a condition where the body’s mast cells — a type of immune cell involved in allergic responses — release too many chemical mediators (like histamine) at inappropriate times.

• Common features: flushing, itching, hives, swelling, GI symptoms (nausea, diarrhea), headaches, or even anaphylaxis-like reactions.

• Why it matters in POTS: The chemical mediators released can cause blood vessels to dilate and leak, further complicating blood pressure regulation and contributing to lightheadedness, fatigue, or sudden drops in blood pressure.

  
  

How Are They Connected?

Research and clinical experience show a strong overlap between POTS, hEDS, and MCAS. Some studies suggest up to 30–50% of people with POTS may also have features of EDS or MCAS.

• EDS → weak connective tissue → blood pooling → worsens POTS symptoms.

• MCAS → mast cell chemical release → vessel dilation/leakiness → worsens POTS symptoms.

• Combined effect: When both are present, they can make POTS harder to manage — but also highlight the need for a comprehensive, personalized approach.

  
  

What This Means for Patients

If you have POTS, it’s worth asking your provider if you might also have symptoms of EDS or MCAS. Understanding the overlap can help guide treatment plans:

• For EDS: focus on joint protection, physical therapy, and compression wear.

• For MCAS: consider trigger avoidance, antihistamines, or mast cell stabilizers (under medical guidance).

• For POTS: hydration, salt, exercise, lifestyle strategies, and medication as needed.

  
  

At Galene Health, we work with patients to treat the whole picture, not just one piece of the puzzle. By addressing each condition, we aim to help patients regain balance — and find their calm again. 🌊

✨ Have questions? Book an appointment with us in Bellingham or via telehealth anywhere in Washington State. You don’t have to navigate these conditions alone.