What is Mast Cell Activation Syndrome?—All You Need to Know!

Written By


Expert Reviewed By

Dr. Lauryn Lax, OTD, MS

Dr. Lauryn, OTD, MS is a doctor of occupational therapy, clinical nutritionists and functional medicine expert with 25 years of clinical and personal experience in healing from complex chronic health issues and helping others do the same.

What Is Mast Cell Activation Syndrome - Woman Usig Her Laptop To Search For Answers

Perhaps you might heard about mast cell activation syndrome. This article will give you the best answer to the question: “what is Mast Cell Activation Syndrome?

What is Mast Cell Activation Syndrome?

Mast Cell Activation Syndrome (MCAS) is a health condition wherein the immune system gets upregulated and goes haywire! As a result, the patient experiences all sorts of physical and mental imbalances as the body goes into “fight or flight” mode with symptoms ranging from GI complaints like IBS, nausea and vomiting, to dizziness and brain fog, itchy skin and acne, thinning hair, heart palpitations, bodily swelling and beyond.

Unfortunately, many healthcare practitioners are not trained to assess, much less provide support and strategies, for patients experiencing Mast Cell Activation Syndrome (MCAS). As a result, many go misdiagnosed for years, or perhaps worse, are told their symptoms are “all in their head” or “nothing is wrong” when they clearly do not feel well.

That is exactly what happened to me.

My MCAS Story

I went undiagnosed for about 18 months before I ever heard the acronym “MCAS” from a, now, health mentor of mine, Dr. Neil Nathin.

What Is Mast Cell Activation Syndrome - Black Mold

After living in a home with toxic black mold for about two years, I became sick. Really sick. My health progressively deteriorated during my residency there and, unbeknownst to me, it was my mysteriously toxic environment—not my body—that was “giving out” on me. Over the course of my stay, I was diagnosed with over 10 chronic conditions I had never had before—asthma, lupus, Hashimoto’s, colitis, migraines, lyme disease and co-infections, allergies, food sensitivities, diabetes, anxiety and panic attacks, SIBO (just to name a few). The solution? Prescription. After prescription. After prescription.

Until Dr. Nathan shared the full story with me of what was really happening in my body.

If you’ve wondered “what is Mast Cell Activation Syndrome?!”, or if you possibly have signs and symptoms of the condition, read on for all you need to know. 

What are mast cells? 

Mast cells are immune cells that act like a “bridge” between the immune system and the nervous system—responding to the stress response, pathogens, toxins and inflammation by releasing histamine when they sense a threat or stress, or serotonin when a “feel good” stressor comes their way, helping you feel happy, calm and at peace.

Mast cells also act like bumper lanes of your immune system to keep your innate immune cells and adaptive immune cells in balance.

Ultimately, the primary role of mast cells is to co-ordinate the immune response to pathogens and to toxins—from mold to chemicals, pesticides, viruses, pathogenic bacteria and any other sources of threat (food triggers, EMF’s, certain scents, VOC’s and off gassing from materials, nail polish paint fumes, bright blue lights, etc.). 

What are typical symptoms of mast cell activation syndrome?

Here’s a picture of a resting mast cell, compared to an activated mast cell. As you can see, there is a little bit of fight or flight going down.

What Is Mast Cell Activation Syndrome?

MCAS symptoms are diverse and look differently for everyone. Some common symptoms of mast cell activation syndrome include:

GI symptoms: Rapid onset after eating or drinking of sweating, flushing, palpitations, itching, swelling of the tongue, bloating, gas, pain, nausea, vomiting and diarrhea.

General: Fatigue, Temperature dysregulation, weight loss or gain.

Sinus/Oral: Itching in throat, post-nasal drip, congestion, sinusitis, rhinitis & pharyngitis

Cardiovascular: Lightheadedness, weakness, dizziness, vertigo, palpitations, arrhythmias, chest pain, POTS, edema.

Sensitivities: Increase to chemicals (MCS) food, touch, smell, light, sound & EMF

Pulmonary: Wheezing, SOB, “air hunger”, laryngitis and bronchitis.

Skin: Rashes of every description, especially associated with itching, flushing and hives, pustules, lesions 

Pelvic: pelvic pain, bladder pain,  cystitis, vaginitis, & prostatitis

Musculoskeletal: Diffuse, shifting muscle and joint pain (resembling FM) often poorly responsive to treatment.

Brain: Headaches, paresthesias, (often “non-physiologic”), tremors, brain fog, seizures, pseudo-seizures, dyskinesias, and autonomic dysregulation.

Mental health:  Anxiety (often with panic), depression, mood swings (often labile), cognitive impairment with “brain fog” & difficulties with focus, memory and concentration and insomnia. 

Why does mast cell activation syndrome happen to certain people? 

In genetically susceptible individuals, with exposure to specific stimuli (especially mold toxin and infectious agents like Lyme and Bartonella and certain viruses,  mast cells may become activated, meaning over-excited or overstimulated (in up to 10% of the population).

For others, immune susceptible individuals are those who may have experienced an enormous amount of stress, trauma or overactivation of the immune system, such as food poisoning followed by antibiotics, a stressful relationship or loss of a loved one, a procedure or surgery, catching a virus and “never being the same again”, or living in toxic black mold. Just to name a few. 

How is mast cell activation syndrome diagnosed?

What Is Mast Cell Activation Syndrome - A Doctor Writing

MCAS is a clinical diagnosis made by a doctor acutely aware of MCAS and the various signs and symptoms that go along with it.

Some key markers of a patient with MCAS include:

  • Increased sensitivities to foods, smells, environments, light, etc.
  • Random ‘flares’ (ex. One day they can eat broccoli, the next day they react) activities
  • Poor tolerance to lots of supplements (often feel worse with too many)
  • Anxiety over health (not feeling well) or diagnosed with anxiety by other practitioners (“it’s all in your head”)
  • Not feeling like themselves (they will say this often)
  • Histamine sensitivity
  • Report “nothing helps”

Why does mainstream medicine not recognize mast cell activation syndrome? 

Sort of like mainstream medicine said “leaky gut” did not exist 10 years ago (and now there are over 17,000 papers on PubMed on “intestinal permeability”), MCAS is a syndrome not currently addressed by many conventional medicine textbooks.

However, “Mastocytosis” (the most progressed, diseased stage form of mast cell activation) is recognized. Mastocytosis is very rare, affecting approximately 2.6 in 10,000 people

Mastocytosis is basically full blown disease form of MCAS, sort of like Addison’s or Cushing’s Diseases for “adrenal fatigue”. In Mastocytosis, mast cells form together in aggregates of 15+ cells each and often release elevated levels of tryptase—an enzyme that is released, along with histamine and other chemicals, from mast cells when they are activated.

Basically the bottom line is: If you have MCAS, your mast cells release mediators too frequently and too often—different from mastocytosis, wherein when your body makes too many mast cells. 

How do you calm down the mast cell response?

I wish “stabilizing” the mast cell activation syndrome was as easy as snapping your fingers or telling your body to “stop freaking out”, but it’s not always that easy. Sometimes the body is so hyper-reactive that it cannot even handle water or eating green things.

This is why I suggest the following 3 step process to most of my clients with MCAS for stabilizing an upregulated immune system. One should not only ask, “what is Mast Cell Activation Syndrome

Join Waitlist We will inform you when the product arrives in stock. Please leave your valid email address below.

No fields found, please go to settings & save/reset fields