Is It Anxiety… or Histamine?
About a year ago I was talking with a friend about her anxiety.
She was telling me all about her symptoms, what had been helping, what hadn’t… and then she said something that gave me a huge piece of the puzzle:
“What’s crazy,” she said, “is my anxiety almost always goes away in the spring when I start taking over-the-counter allergy pills. That couldn’t be connected, right?”
Actually, it could.
But why would an allergy pill impact someone’s anxiety?
When we think of anxiety, we usually think of the brain—neurotransmitters, stress hormones, or past experiences that shaped how our body reacts to stress. But more and more research is showing that for some people, a hidden immune or histamine issue can quietly fuel those same anxious sensations.
Let’s unpack that connection and talk about what you can do if histamine might be contributing to your stress response.
What Exactly Is Histamine?
Most people only hear about histamine during allergy season, but it’s far more than a sneeze signal.
Histamine is a chemical messenger that your body uses in two major ways:
As part of your immune response - it’s released by white blood cells called mast cells whenever your body senses a threat (like pollen, mold, or a food sensitivity).
As a neurotransmitter in your brain - it helps regulate alertness, motivation, and your wake-sleep cycle.
So histamine doesn’t just make your nose run. It also plays a role in how alert—or on edge—you feel.
Your body normally breaks histamine down using enzymes like DAO (diamine oxidase, made in your gut) and HNMT(found in tissues). But when you make too much histamine, or those enzymes can’t keep up, histamine builds up in your system.
In other words: histamine is meant to send short “hey, wake up and defend” messages. But if those alerts never turn off, your body can feel like it’s always on high alert.
Why Histamine Can Feel Like Anxiety
Histamine and anxiety feel similar because they activate the same parts of the body. When histamine levels are high, you might feel:
Jittery or restless
Heart racing or pounding
Flushed or overheated
Sensitive to light, sound, or smells
Wired but tired
Sound familiar? Those are also common symptoms of being stuck in a fight-or-flight state.
Research has found that histamine interacts directly with the brain’s stress centers—especially the amygdala and hypothalamus. These are the same regions that control anxiety, fear, and the release of cortisol (your main stress hormone).
That’s why some people notice that an antihistamine (like hydroxyzine) can help calm anxiety—it literally dampens that histamine signal.
For a lot of people this explains why they might have a panic attack when they’re just sitting on the couch calmly reading. No outside trigger is happening, but something internal is creating that response. Histamine is one of those potential triggers.
When Histamine Runs Wild: Mast Cell Activation Syndrome (MCAS)
If histamine is the message, mast cells are the messengers. They live in your skin, lungs, gut, blood vessels, and even around nerves in your brain. They store histamine, ready to release it when something seems unsafe.
In Mast Cell Activation Syndrome (MCAS), those cells become overreactive—releasing histamine and other inflammatory chemicals too easily or too often. Sometimes it’s from mold exposure, chronic infection, gut issues, or stress. Sometimes it’s unclear why.
MCAS symptoms can look like:
Flushing or hives that come and go
Digestive issues that flare for no reason
Headaches, dizziness, or rapid heartbeat
Sensitivity to smells, temperature, or chemicals
Feeling anxious, overstimulated, or “on edge”
Think of it this way: mast cells are your body’s security guards. In MCAS, they’ve started sounding the alarm for every squirrel that runs by.
And yes—research now shows that people with MCAS are statistically more likely to struggle with anxiety, depression, and other mood disorders. When your mast cells are constantly releasing histamine, it doesn’t just affect your sinuses—it affects your nervous system’s sense of safety.
(MCAS as a diagnosis has only been on the scene since about 2016. Previously, people with MCAS were usually diagnosed with Multiple Chemical Sensitivity.)
Why Gut Health Plays a Huge Role
Most of your DAO enzyme—the main one that breaks down histamine—is made in your gut lining. So if you have leaky gut, SIBO, or dysbiosis, your body may not be clearing histamine efficiently. Add in a microbiome that’s producing extra histamine, and you have a recipe for feeling anxious and inflamed.
Your gut isn’t just where you digest food; it’s where your nervous system gets a lot of its “safety” signals. A reactive gut means a reactive brain. This is why so much comes back to healing the gut!
Signs Histamine Might Be Fueling Your Anxiety
If you relate to several of these, it might be worth exploring:
You feel restless, hot, or flushed for no clear reason
Your anxiety flares after eating certain foods (wine, chocolate, leftovers, fermented foods)
You’re sensitive to smells or temperature changes
You get headaches, congestion, or itching alongside anxiety
Antihistamines help you sleep or calm down
Your anxiety feels “physical”—heart pounding, stomach upset, jittery energy
None of these confirm a histamine issue, but they can be important clues.
What You Can Do
I’m not here to diagnose, only to help you connect dots and have an informed conversation with your provider. Here are some gentle, practical steps you can take (with professional guidance):
Try a short low-histamine experiment
For 2–3 weeks, limit high-histamine foods like aged cheese, wine, fermented foods, vinegar, processed meats, and long-stored leftovers. Focus on fresh, simple meals—think freshly cooked proteins, vegetables, fruits (except citrus, tomatoes, and strawberries), and gluten-free grains.
This isn’t forever. It’s just a short experiment to see if your body feels calmer when histamine is lower.Support your gut
Since DAO lives in your gut, improving gut health helps regulate histamine naturally. That means:
- Eating slowly and mindfully
- Addressing constipation or bloating
- Reducing alcohol and processed foods
- Including nutrients that support gut lining repair (like zinc, glutamine, and omega-3s)Be mindful with leftovers
Histamine rises the longer food sits, even in the fridge. Cook fresh when possible, freeze extras right away, and avoid long-simmered broths or soups that sit for hours before cooling.\Support your body’s natural histamine breakdown
Nutrients that help include Vitamin C, B6, magnesium, and copper (through whole foods first). Certain supplements like quercetin or DAO enzyme may be helpful short-term—but work with a practitioner to find the right fit.Regulate your nervous system
Even if histamine is part of the story, your nervous system still needs to learn safety. Practices like deep breathing, EFT tapping, or Aroma Freedom Technique can help shift you out of fight-or-flight.
When your body feels safe, your immune system relaxes, too.
A Gentle Reminder
Not everyone with anxiety has a histamine problem, and not everyone with histamine issues feels anxious. But if you’ve tried the usual tools—therapy, medication, meditation, supplements—and still feel “revved up” for no reason, this could be a missing piece worth exploring.
The best next step is to work with a practitioner who understands both the immune system and the nervous system—someone who can guide you through testing, food trials, and safe experimentation.
And remember: your goal isn’t to chase another diagnosis. It’s to understand your body better, so you can give it what it actually needs.
One doctor to check out who specializes in MCAS is Dr. Stephanie Peacock. CLICK HERE to learn more.
A final note
Inside my Rooted + Rising membership, we focus on the foundations that help calm both the body and the mind—sleep, nourishment, movement, and connection.
Because for most people, it’s not a lack of knowledge holding them back—it’s the follow-through. That’s why I include a monthly Aroma Freedom Technique coaching session to help release the patterns that keep you stuck, so you can create lasting change from the inside out.
