If This Pattern Sounds Familiar, It Might be Time to Learn About MCAS
Have you been told your symptoms are “just anxiety,” “just hormones,” or “just stress”—even when something deeper tells you it’s more than that?
If this pattern sounds familiar, you’re not alone. It might be time to learn about mast cell activation syndrome (MCAS).
The Pattern So Many People Know Too Well
Here are just a few common MCAS-related symptoms—and the dismissive responses people often hear in return:
Can’t sleep? “Just poor sleep hygiene.”
Food intolerances? “That’s just IBS.”
Lightheaded? “You’re just anxious.”
Struggling to focus? “You must be lazy or tired.”
Exhausted all the time? “Maybe stop complaining.”
Mood swings? “It’s probably hormonal.”
Short of breath? “Just out of shape.”
Flushing, sneezing, or itching? “It’s just allergies.”
Cold hands and feet? “Must be poor circulation.”
Daily headaches or migraines? “You’re just stressed.”
These symptoms are often written off as unrelated, exaggerated, or purely psychological. But what if they’re actually connected?
What Is MCAS?
Mast cell activation syndrome (MCAS) is a condition where mast cells—a type of immune cell—release excessive amounts of chemicals like histamine, prostaglandins, and cytokines throughout the body. These chemicals can affect nearly every organ system, causing a wide range of symptoms that come and go, change over time, and often seem unrelated.
This is what makes MCAS so commonly overlooked—its symptoms mimic other conditions and are often dismissed as being “in your head.”
MCAS Is More Common Than You Think
Contrary to popular belief, MCAS is not rare. Estimates suggest that up to 17% of the general population—roughly 1 in 6 people—may be affected by mast cell dysfunction. Yet most are undiagnosed.
Why? Because it doesn’t always show up in obvious ways. And when the symptoms are invisible or misunderstood, people are often misdiagnosed with:
Irritable bowel syndrome (IBS)
Generalized anxiety disorder
Chronic fatigue
Panic attacks
Depression
Functional neurological symptoms
Fibromyalgia
“Medically unexplained” issues
You’re Not Lazy. You’re Not Imagining It.
If you’ve been dismissed by doctors or told your symptoms are due to laziness, attention-seeking, or anxiety—it’s not your fault.
MCAS can cause:
Unrelenting fatigue
Brain fog
Pain and inflammation
Food and chemical sensitivities
Cardiovascular symptoms like racing heart or low blood pressure
Neurological symptoms like tingling, dizziness, or cognitive difficulty
And no, you don’t have to have hives or rashes for MCAS to be real.
Related Conditions: POTS and EDS
Many people with postural orthostatic tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder (HSD) also experience MCAS. These conditions are part of what’s sometimes called the trifecta:
EDS/HSD (connective tissue disorder)
POTS (dysautonomia)
MCAS (immune dysregulation)
They frequently overlap, especially in people with chronic, unexplained symptoms from a young age.
If you recognize yourself in this pattern, it doesn’t mean MCAS is definitely the cause—but it’s worth exploring.
The first step is awareness. The next step is validation. From there, you can work with a knowledgeable healthcare provider to start connecting the dots and building a plan that supports your body.
Want expert tips for living well with MCAS?
Join Dr. Gould’s Neurenity Notes—a free, down-to-earth newsletter with helpful ideas, real-life strategies, and support for navigating MCAS, sent right to your inbox.
PMID: 38003876; PMID: 30794367; PMID: 32328892
Disclaimer: This blog post is for informational purposes only and shall not be construed as behavioral health or medical advice. It is not intended or implied to supplement or replace treatment, advice, and/or diagnosis from your own qualified healthcare provider.