Is It Anxiety, or Is There More? How Mast Cells Can Play a Role in Anxiety
The WellSpring | Well Mind Body Blog
Does your heart races when you stand up? Do you feel flushed, itchy, dizzy, or foggy? Does your stomach feel unsettled, and a wave of panic seems to come out of nowhere? Maybe you’ve been told it’s anxiety or maybe you’ve even started to believe it’s all in your head?
For many people, anxiety makes sense. For others, anxiety is part of a bigger picture that involves the immune system, the autonomic nervous system, and even the environment they live in. Three connections are worth understanding: mast cells, POTS, and environmental exposures like mold.
What Are Mast Cells?
Mast cells are immune cells found throughout the body. They’re especially common in places that meet the outside world, such as the skin, gut, airways, and blood vessels. They also live near nerves and in the brain.
When mast cells sense a threat, they release chemical messengers, including histamine. This is typically a healthy, protective response. Histamine is also a neurotransmitter in the brain, where it plays a role in alertness and wakefulness.
In mast cell activation syndrome (MCAS), mast cells release these chemicals a bit too easily and too often. Because mast cells are everywhere, symptoms can show up in many body systems at once:
Skin: flushing, itching, hives, swelling
Heart and circulation: rapid heartbeat, lightheadedness, blood pressure changes
Digestion: nausea, cramping, bloating, diarrhea
Airways: congestion, wheezing, throat tightness
Nervous system: brain fog, headaches, fatigue, sleep problems
Mood: anxiety, panic, irritability, low mood
Many of these overlap with the physical sensations of anxiety and panic. That’s one reason MCAS can be mistaken for “just anxiety,” and anxiety can be mistaken for MCAS.
What the Research Shows About Mast Cells and Anxiety
Anxiety is common in people with MCAS
Research shows that anxiety and related conditions are much more common in people with MCAS. A multicenter study compared 553 people with MCAS to 558 people without it. Women with MCAS were about four times more likely to report an anxiety disorder (65.9% compared with 30.3%) and more than three times more likely to report panic disorder. People with MCAS also reported higher rates of depression, PTSD, and obsessive-compulsive disorder (Weinstock et al., 2025).
Some patients improve when mast cells are treated
In a case series of eight patients with MCAS and long-standing conditions such as generalized anxiety disorder, panic disorder, and depression, all eight improved with mast-cell-directed treatment. Most returned to work or school (Weinstock et al., 2023).
Not every case of suspected MCAS is MCAS
A study of 592 adults who had been told they might have MCAS found that only about 43% reported symptoms matching the first diagnostic criterion. More than a third tested positive for other conditions. Signs of anxiety (34%) and depression (39%) were common across the whole group (Gutsche et al., 2026).
POTS: When Your Heart Races Every Time You Stand
Postural orthostatic tachycardia syndrome (POTS) is a condition of the autonomic nervous system, the part of the nervous system that controls heart rate, blood pressure, and digestion without you thinking about it. In POTS, the heart rate rises sharply when a person stands up. That can cause dizziness, a pounding heart, shakiness, fatigue, brain fog, and nausea.
Those sensations feel very similar to a panic attack, so POTS is often mistaken for anxiety. In a survey of 227 young adults who had been diagnosed with POTS in childhood, nearly three-quarters experienced delays in getting diagnosed, and more than half were told their symptoms were “in their head.” Almost all of them (99%) still had symptoms years later (Boris et al., 2024).
POTS and MCAS often occur together. In the case series described above, half of the patients with MCAS and psychiatric symptoms also had POTS, and half had hypermobile Ehlers-Danlos syndrome, a connective tissue condition that often appears alongside both (Weinstock et al., 2023).
Signs it may be worth asking about POTS:
Your heart races, or you feel faint or dizzy, when you stand up
Symptoms get worse with heat, long periods of standing, or after meals
You feel better lying down
“Anxiety” episodes seem tied to changes in position rather than to worry
Environmental Exposures: Mold and the Brain
The environment we live in can also affect how we feel. Damp, water-damaged buildings can grow mold, and growing research links mold exposure to mood symptoms.
Research shows that people exposed to mold at home are more likely to experience anxiety and depression. A study of more than 9,200 adults aged 65 and older found that those who reported frequent musty or moldy odors at home were about twice as likely to have anxiety and more than twice as likely to have depression. They were also more likely to have both at once (Ma et al., 2025).
Mold is also a commonly reported trigger for people with mast cell problems.
CIRS
Chronic inflammatory response syndrome (CIRS) is long-lasting, body-wide inflammatory illness, triggered by exposure to water-damaged buildings, mold or other environmental factors. People diagnosed with CIRS often report fatigue, brain fog, headaches, mood changes, and symptoms in many body systems. That picture overlaps with MCAS, POTS, and anxiety.
Is It Anxiety or Something More?
Often, it’s both. The mind, immune system, and nervous system are in constant communication. A racing heart, flushing, or dizziness can trigger anxious thoughts, and stress can make physical symptoms worse. That loop can be exhausting, especially when your concerns are dismissed as “just anxiety.”
It may be worth talking with your doctor about MCAS, POTS, or environmental exposures if:
Your anxiety comes with physical symptoms in several body systems at once, such as skin, gut, heart, and breathing
Symptoms flare when you stand up, or with heat, certain foods, smells, or medications
Symptoms began or worsened after time in a damp or moldy home, school, or workplace
You have hypermobility or a family history of these conditions
Standard anxiety treatment has helped only partly
These conditions are diagnosed by medical providers, often a cardiologist, allergist or immunologist, or integrative physician. Please don’t start or stop medications on your own.
How Well Mind Body Can Help
At Well Mind Body, we see the mind and body as one connected system. Whether your anxiety is driven by stress, by your immune or nervous system, by your environment, or by all of these, you deserve care that takes the whole picture seriously.
We can help you:
Calm your nervous system with mind-body and nervous system regulation tools
Break the anxiety–symptom loop, so physical sensations feel less frightening
Process the stress of living with chronic, confusing, or dismissed symptoms
Connect with trusted medical providers, including cardiology and functional medicine, who can evaluate POTS, mast cell, and environmental concerns
Book a session at Well Mind Body
Well Mind Body Integrative Psychotherapy & Wellness
3801 Kirby Drive, Suite 344, Houston, TX 77098
In person in Houston and virtually throughout Texas
Thanks for being here,
Dr. E
References
Boris, J. R., Shadiack, E. C., McCormick, E. M., MacMullen, L., George-Sankoh, I., & Falk, M. J. (2024). Long-term POTS outcomes survey: Diagnosis, therapy, and clinical outcomes. Journal of the American Heart Association, 13(14), Article e033485. https://doi.org/10.1161/JAHA.123.033485
Gutsche, A., Buttgereit, T., Buchkremer, R., Panse, J., Kreddig, N., Ptock, O., Roll, S., Grabowska, W., Aulenbacher, F., Metz, M., Pyatilova, P., Salameh, P., Pereira, M. P., & Siebenhaar, F. (2026). A real-world cross-sectional study on suspected mast cell activation syndrome: Multiple heterogeneous symptoms identified. Clinical and Translational Allergy, 16(7), Article e70184. https://doi.org/10.1002/clt2.70184
Ma, X., Zhao, H., Wang, Y., Hou, M., Liu, W., [remaining authors], & Sun, M. (2025). Association of mold exposure and solid household fuel use with depression and anxiety among older adults in China. Environmental Health, 24, Article 50. https://doi.org/10.1186/s12940-025-01193-4
Weinstock, L. B., Afrin, L. B., Reiersen, A. M., Brook, J., Blitshteyn, S., Ehrlich, G., Schofield, J. R., Kinsella, L., Kaufman, D., Dempsey, T., & Molderings, G. J. (2025). Prevalence and treatment response of neuropsychiatric disorders in mast cell activation syndrome. Brain, Behavior, & Immunity – Health, 48, Article 101048. https://doi.org/10.1016/j.bbih.2025.101048
Weinstock, L. B., Nelson, R. M., & Blitshteyn, S. (2023). Neuropsychiatric manifestations of mast cell activation syndrome and response to mast-cell-directed treatment: A case series. Journal of Personalized Medicine, 13(11), Article 1562. https://doi.org/10.3390/jpm13111562
