Why Do I React to Everything? My MCAS Story

I thought I was doing everything right. I just didn't know I was doing it the wrong way.

As an athlete, a busy mom, a wife, and a teacher, I meal-prepped the same healthy meals week after week. And week after week, I bloated. I swelled. My energy disappeared. The weight would not come off.

I kept asking myself: why am I not losing weight when I'm doing everything right?

But I'm getting ahead of myself. To understand how I got there, we need to go back a few years... or decades (is my age showing?).

I've dealt with anxiety since I was young. Cystic acne. Being overweight all through childhood. Migraines at 8 years old. Digestive issues that never fully made sense — I'd eat pizza and drink a Coke and feel so sick afterward that I genuinely thought something was wrong with me. I quit drinking soda before I was 12 because it hurt that much.

At 16, I had an EGD for chronic heartburn and reflux. It would wake me up at night — I'd sit up with a racing heart and a wave of anxiety I couldn't explain. Looking back now, I recognize that my body was showing signs of being under a lot of stress. I just didn't have the language for it yet.

At some point I decided to cut out gluten, even without a formal test telling me I needed to. A lot of people told me I was too obsessed, that I didn't have proof I needed to eliminate it. But I felt better. That, along with strength training, helped enough that I kept going.

The acne stuck around, though. Adult acne was so embarrassing! So did the digestive issues, the weight-loss resistance, and the migraines. I never seemed to have enough energy to make it through a full day without crashing. My periods were bad enough to put me in bed for a day or two every month.

And no matter what I did — dieting, training, staying in a deficit — my weight wouldn't move consistently. If I did manage to lose it, it came right back.

Then, in my late 20s, after COVID and a stretch of career stress, everything got significantly worse.

Chest pain. Heart palpitations. Anxiety that wouldn't quit. Exhausted but wired at the same time. My body couldn't seem to regulate its own temperature. I fainted a few times during emotionally stressful moments. I remember lying on the bathroom floor in the middle of the night after a bad flare because I was too weak to move or even call for help.

I started looking for answers.

I saw a cardiologist, multiple internal medicine doctors, a neurologist, several PCPs, an endocrinologist, and functional medicine doctors. I wore a Holter monitor. I had test after test.

Again and again, I was told everything was "normal." None of it added up to a real answer — just a pile of tests and a growing list of things to manage.

The treatment options I was offered mostly focused on managing one symptom at a time — hormonal birth control, antidepressants, Singulair, Allegra, Pepcid, and advice like "exercise more, eat less." At one point I was prescribed a very low dose of progesterone, and it left me with significant muscle weakness, chest pain, and extreme fatigue for six weeks.

My doctors, my trainers, and even I landed on the same answer: it must be the calories. It must be the food.

So I changed the food.

Add more veggies. Cut the fat. Add the fat back. Cut the veggies. Try gluten-free. Try dairy-free. Try no eggs.

Nothing changed.

Same result every time: bloating, gas, swelling, headaches, insomnia.

Every once in a while I'd have a good week — slim, strong, feeling like myself. Then it would disappear again, stolen by something I couldn't name.

I figured it had to be me.

Then it got worse.

Fragrances started bothering me. So did temperature changes. I started having heart palpitations, nausea, migraines, and a fatigue that went bone-deep.

Why am I reacting to everything?

It was the same story I'd been living for years — just louder now. First they told me it was my thyroid. Then they said it wasn't.

And still, nobody was offering to find out why the symptoms were happening in the first place.

Finding the Name for It

I found the answer scrolling Instagram, of all places.

A physician had posted a list of symptoms tied to something called Mast Cell Activation Syndrome, or MCAS: heart palpitations, PCOS, endometriosis, histamine intolerance, food sensitivities, flushing, trouble regulating body temperature, reacting to the environment, frequent urination, nausea, bloating, weight-loss resistance, insulin resistance.

That list was my life.

Retrospectively, I'd been dealing with MCAS for a lot longer than I realized — it was COVID that threw me over the edge.

As a child, I would faint, feel nauseous, get bloated, gain weight I couldn't explain, and feel so tired I had to ask my sibling to do my "dirty work" (laundry, ha!). I struggled in school. The brain fog was real.

But finding a name for it didn't mean I had found the answer I was looking for.

I Divorced My Doctors

After I learned about MCAS on my own, I brought it to my internal medicine doctor.

I liked him — he was open-minded and supportive. But his solution was the same short list of medications I'd already been living on.

I know they help, and I used them. I relied on them for a while.

But I wasn't looking for symptom management.

I was looking for remission.

A lifetime of medication to manage my symptoms just enough to be functional doesn't fit my personality. I like to imagine myself surviving a zombie apocalypse — and I can't do that if I have to live at the pharmacy for drugs or risk failing.

I know that's never actually going to happen, but the principle is the same.

I divorced that doctor and found a functional medicine doctor who specialized in MCAS.

He officially diagnosed me with MCAS, POTS, and PCOS — finally, names for what my body had been doing to me for years.

But he threw information and medical jargon at me like glitter — and as someone who loves research, I'll admit I was a little distracted by the shine.

Once the shine wore off, the plan was the same shape as before: try this GLP, take this medication, add this supplement.

So I tried them.

What I didn't know at the time was that my body wasn't ready for the GLP — it didn't work for me, though it works great for plenty of other people. That's the nature of MCAS: what works for one person doesn't always work for the next.

That's a story for another post.

When I finally asked him how we'd figure out what actually caused this, and how to put it into remission, his answer was: reduce your stress, stop working out.

And that was it.

Divorced again.

By that point, I'd had enough.

So I got on ChatGPT and asked it to help me find a program — something that would let me use my strong science background to heal myself and help other people do the same.

That's how I found Functional Diagnostic Nutrition®.

FDN taught me how to connect everything I already knew about the body to the nervous system, and to the idea of upstream stressors and their downstream effects.

My symptoms — and even the MCAS diagnosis itself — weren't the actual problem.

They were the result of hidden stressors underneath.

So What Is MCAS?

Mast cells are immune cells that act like your body's security guards. They're always on watch, ready to sound the alarm the moment they sense danger — a virus, a toxin, an allergen.

Each mast cell is covered in receptors — think of them as keyholes. When something fits into one of those keyholes and turns it, a "door" opens and the cell releases chemical messengers into your body, including histamine.

That's a normal, healthy, protective process.

In MCAS, this alarm system gets stuck in overdrive. It opens doors too easily, too often, and sometimes for no reason a lab test can catch.

And because mast cells sit in tissue all over the body — skin, gut, lungs, blood vessels, nervous system — the chemicals they release can cause symptoms almost anywhere.

That's why MCAS can look like a dozen different problems at once, and why it's so easy for both patients and doctors to miss.

One of the hardest parts about pinning down my triggers was that there wasn't just one thing to blame.

It's a bit like walking into a classroom where every student is a version of "Bob" and they all sort of look alike — good luck picking out the right Bob.

With this many possible triggers and this many possible symptoms, MCAS can hide in plain sight for years.

It's Not Random — Even When It Feels Random

The scent of a candle. A cleaning spray. Pollen. A lotion.

Something totally "normal" can trigger a system-wide reaction.

That's not you being dramatic — it's a nervous system and immune system that have become dysregulated.

For a lot of people, that dysregulation traces back to something underneath it: mold exposure, Lyme disease, a past viral infection like Epstein-Barr, a traumatic brain injury, long COVID, or unresolved chronic stress or trauma.

MCAS is very often a symptom of something else going on, not a stand-alone problem — which is exactly why root-cause testing matters so much more than symptom management.

Wait — Isn't Histamine a Bad Thing?

Not at all.

Histamine is necessary.

If cortisol is the key that starts your car, histamine is part of what keeps the engine running once you're moving.

Here's an example: someone slams on their brakes in front of you in traffic. Your body needs to react instantly. Stress hormones like adrenaline and cortisol flood your system, and part of what they do is activate mast cells to release histamine.

That histamine helps keep your nervous system on high alert — heart pumping faster, senses sharper — for as long as you need to stay safe.

Once the danger passes, your body is supposed to power back down.

In MCAS, that "power down" switch doesn't work right. The alert system stays too sensitive, too long, and starts responding to things that were never actually dangerous.

Why "Just Manage It" Isn't Good Enough

Plenty of physicians will tell you MCAS can't be cured or put into remission — that you just have to manage your symptoms and your stress — and then send you out the door with no real plan for how to do that without a prescription pad.

And the medications don't always help much, because with so many different receptors involved, one medication might calm one or two pathways while a dozen others are still wide open.

That's not a reason to give up.

It's a reason to look upstream — at the gut, at environmental exposures like mold, at old infections — instead of only chasing symptoms one at a time.

That's what I finally started doing.

I ran my own labs. I did the coursework. I passed the tests and built my own protocol.

Eight months later, I can still feel the shift.

First the chronic bloating and gas went away. Then the acne cleared. Then my flares got less severe, and I could sleep through some nights without relying on medication. My Oura ring even started showing better resiliency scores and improved sleep.

Where I Am Now

Today, I'm almost the best I've ever been.

That's a huge accomplishment coming from someone who lived at rock bottom for years.

I no longer take Allegra every night. I don't flare when I eat histamine-rich food. I don't always flare after leg day, or after a stressful day, or when I have a disagreement with my husband, or when the classroom makes me crazy. I don't flare when I go over 10,000 steps. I don't always flare when I try a new supplement for experiments.

I still flare when I ovulate, when it rains, and when I get too cold in the winter.

But I'm better.

I still have a long way to go, but I'm learning — and that's exactly the work I now get to do with clients at Rootera Wellness: finding the why behind the symptoms, instead of managing them forever.

More to come.

Sources referenced: Weiler CR, et al. "Mast Cell Activation Syndrome: Tools for Diagnosis and Differential Diagnosis." J Allergy Clin Immunol Pract. "Using the Right Criteria for MCAS." Current Allergy and Asthma Reports, 2024.