Could It Be MCAS?
The Symptoms You’ve Been Told to Ignore—Now, Finally Explained
Mast Cell Activation Syndrome (MCAS) can affect nearly every system in the body. That’s because mast cells—your immune system’s frontline messengers—are everywhere: in your skin, gut, brain, lungs, and nerves. When they become overactive, they release chemical signals like histamine at the wrong time, in the wrong place, and in the wrong amounts.
If your symptoms seem random, change daily, or worsen after triggers like Covid, mold, Lyme disease, hormones, or stress, you’re not imagining it—and you're not alone.
Not everyone with MCAS has all these symptoms—and not every symptom means MCAS. But if you’re checking more boxes than not, it's time to look deeper.
Neurological & Cognitive
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Brain fog
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Memory issues
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Anxiety, panic attacks, or irritability
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Depression
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Light or sound sensitivity
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Headaches or migraines
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Sleep disturbances
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Internal vibrations or tremors
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Dizziness or feeling faint
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Depersonalization or disorientation
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Motion sickness
Gastrointestinal
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Bloating or visible belly swelling
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Nausea or early fullness
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Diarrhea or constipation
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Acid reflux
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Abdominal pain or cramping
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Food intolerances that keep increasing over time
Dermatological (Skin)
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Itching with no rash
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Hives
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Flushing (especially on face or chest)
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Rashes or eczema
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Swelling of hands, lips, or face
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Dermatographia (skin writing)
Cardiovascular / Autonomic
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Heart palpitations
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Low blood pressure or feeling faint
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Feeling “wired but tired”
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Heat intolerance or temperature dysregulation
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Exercise or activity crashes
Respiratory
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Shortness of breath (especially after eating or exposure)
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Postnasal drip or sinus congestion
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Asthma-like symptoms with normal tests
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Air hunger or shallow breathing
Hormonal & Reproductive
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PMS, PMDD, irregular periods
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Infertility
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Histamine flares with ovulation or menstruation
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Hair loss or thinning
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Fatigue that doesn’t improve with rest
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Worsening symptoms around ovulation, stress, or heat
Post-Covid MCAS looks different. It often includes neurological symptoms like brain fog, limb numbness, neuropathy, burning skin sensations, hair loss, and new sensitivities that didn’t exist before. You’re not broken.
You’re inflamed—and there’s a path back.
Uncommon (But Increasingly Recognized) Symptoms of MCAS which are oftentimes associated with Long Covid
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Air starvation or air "gulping"
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Tinnitus (ringing in the ears)
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Frequent urination or interstitial cystitis
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Burning mouth or tongue
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Bone/joint pain
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Visual disturbances
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TMJ or jaw pain
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Electrical zaps or nerve pain
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Tremors (or "earthquakes")
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Sudden weight gain or loss
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Food-related mood crashes
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Chemical sensitivity
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Chronic cough or throat-clearing