POTS is mainly a problem with the part of the nervous system that controls heart rate and blood flow when you stand, but for many people the immune system appears to be tangled up in it too.1PubMed. Postural Orthostatic Tachycardia Syndrome: Prevalence, Pathophysiology, and Management Researchers increasingly describe an immune-related type of POTS, one of several overlapping types rather than the explanation for everyone. No clear autoimmune cause has been identified, so POTS isn’t officially an autoimmune disease.2Cleveland Clinic Journal of Medicine. Autoimmunity and postural orthostatic tachycardia syndrome: Implications in diagnosis and management An immune link usually points to an overactive or misdirected immune response, not a weak one that leaves you open to every cold.
Antibodies That Target Your Own Nerves and Blood Vessels
Autoantibodies are immune proteins that attack parts of your own body instead of germs. In POTS, the ones found most often are aimed at receptors on blood vessels and nerves. In one group of patients, 89% had raised autoantibodies against the alpha-1 receptor, a switch that tells blood vessels to tighten.3PubMed Central. Postural Orthostatic Tachycardia Syndrome Is Associated With Elevated G‐Protein Coupled Receptor Autoantibodies In the same patients, 53% had raised autoantibodies against a receptor tied to the calming side of the nervous system.4PubMed Central. Inflammatory Biomarkers in Postural Orthostatic Tachycardia Syndrome with Elevated G-Protein-Coupled Receptor Autoantibodies Another study found about 3 in 10 POTS patients had antibodies against nerve junctions that relay automatic signals.5PubMed Central. Autoimmune postural orthostatic tachycardia syndrome Antibodies against angiotensin receptors and heart proteins have also turned up.6Oxford Open Immunology. Autoimmunity in Long Covid and POTS
Those numbers overlap because receptors for different signals sit side by side on the same vessels and nerves, so one person can carry several kinds of antibody at once. The percentages from different studies don’t add up to separate groups of patients. The percentages come from research labs that measure antibody activity on receptors, using methods that differ from a standard hospital blood test. “Raised” means higher than the comparison group in that study, not a diagnosis of a named disease.
Here is how antibodies could produce symptoms. Normally, when you stand, your blood vessels tighten automatically within seconds, which keeps blood from drifting downward. Antibodies against blood vessel receptors may keep veins from tightening properly, so blood pools in the legs.7Oxford Open Immunology. Autoimmunity in Long Covid and POTS Less blood returns to the heart, and it speeds up to keep blood reaching your brain. That gives you the dizzy, racing-heart feeling on standing. Other antibodies may push heart rate up directly.8Oxford Open Immunology. Autoimmunity in Long Covid and POTS
No direct cause-and-effect link has been proven yet.9Oxford Open Immunology. Autoimmunity in Long Covid and POTS Antibodies can be a result of illness or a bystander rather than the driver. Studies so far are small and mostly come from specialist clinics, and some healthy people carry low levels of similar antibodies.
Inflammation and Immune Cells in POTS
Cytokines are chemical messengers that immune cells use to turn inflammation up or down. People with POTS had higher levels of one inflammation messenger than healthy people of similar weight.10PubMed Central. Sympathetic activation is associated with increased IL-6, but not CRP in the absence of obesity: lessons from postural tachycardia syndrome and obesity CRP, the inflammation test doctors usually order, was low and normal in both groups.11PubMed Central. Sympathetic activation is associated with increased IL-6, but not CRP in the absence of obesity: lessons from postural tachycardia syndrome and obesity So a normal CRP doesn’t rule out immune activity in POTS. Another study found 13 of 14 messengers raised in POTS, both before the pandemic and after COVID.12PubMed Central. Plasma Cytokine and Caspase-1p20 Profiles in Pre-Pandemic and Long COVID-Associated Postural Orthostatic Tachycardia Syndrome Cytokine panels aren’t standard clinical tests, and normal routine results don’t mean your symptoms are imagined.
Immune cells show shifts too. People with POTS had more of certain types of immune cells than expected.13Autonomic Neuroscience. Alterations in peripheral T cell and B cell subsets in patients with postural orthostatic tachycardia syndrome Which cells changed depended on which antibodies a person had, suggesting immune involvement differs between patients.14Autonomic Neuroscience. Alterations in peripheral T cell and B cell subsets in patients with postural orthostatic tachycardia syndrome These results are better read as hints about subgroups than as one signature of POTS. None of this is used in routine care yet. Inflammation may weaken blood vessel tightening, boost the stress-nerve response, and add to fatigue and low mood,15PubMed Central. Non-invasive Vagus Nerve Simulation in Postural Orthostatic Tachycardia Syndrome but its exact role in POTS is still unclear.16PubMed Central. Non-invasive Vagus Nerve Simulation in Postural Orthostatic Tachycardia Syndrome
Mast Cell Problems and Allergy-Like Symptoms
Mast cells are immune cells that release histamine and other chemicals during allergic reactions. In one POTS clinic, about 2 in 3 patients had extra symptoms like migraine, rashes, allergies, or gut trouble.17Journal of the American Heart Association. Mast Cell Activation Disorder and Postural Orthostatic Tachycardia Syndrome: A Clinical Association About 4 in 10 of all patients had both those symptoms and at least one lab marker of mast cell activation, most often histamine or prostaglandins.18Journal of the American Heart Association. Mast Cell Activation Disorder and Postural Orthostatic Tachycardia Syndrome: A Clinical Association When mast cells misfire like this, the condition is called mast cell activation syndrome (MCAS), a name you may hear from your doctor. POTS, MCAS, and hypermobile Ehlers-Danlos syndrome often occur together.19Taylor & Francis Online. Hypermobility spectrum disorder/hypermobile Ehlers-Danlos syndrome, mast cell activation syndrome, and dysautonomia as risk factors for adverse events and complications
Possible hints that your POTS may involve mast cells, not proof on their own, include flushing or hives with a racing heart, symptoms after heat, certain foods, or alcohol, and itching, wheezing, or stomach cramps alongside dizzy spells. Testing can be hard to interpret because mast cells release their chemicals in bursts. A sample taken between flares can look normal even when the problem is real. Histamine and prostaglandin breakdown products can be measured in blood or urine, so ask about testing soon after a flare, since markers fade fast. Samples often need special handling, such as being kept cold, so ask the lab how to collect them. A normal result between flares doesn’t rule out mast cell problems, and an abnormal one needs a doctor to read it alongside your symptoms.
Hormones matter here too. Estrogen can directly activate mast cells, while progesterone may calm them.20PubMed Central. Postural Orthostatic Tachycardia Syndrome, Menopause and Hormone Replacement Therapy: Clinical Decisions in Times of Uncertainty So symptoms may shift with your menstrual cycle, pregnancy, or menopause. It helps to note symptoms by cycle day in a diary and bring the pattern to your doctor.
Higher Rates of Autoimmune Disease
In one large clinic group, 20% of POTS patients had an autoimmune disease, compared with at most about 9% of the general public.21PubMed. Autoimmune markers and autoimmune disorders in patients with postural tachycardia syndrome (POTS) A positive ANA (antinuclear antibody) test, a general marker of autoimmunity, showed up in 25% of POTS patients versus 16% of the general public.22PubMed. Autoimmune markers and autoimmune disorders in patients with postural tachycardia syndrome (POTS) Antiphospholipid antibodies, linked to blood clotting problems, appeared in 7% versus 1%.23PubMed. Autoimmune markers and autoimmune disorders in patients with postural tachycardia syndrome (POTS) Across studies, POTS patients consistently had higher rates of autoimmune diseases, and celiac disease may be among them.24PubMed Central. Sex adjusted standardized prevalence ratios for celiac disease and other autoimmune diseases in patients with postural orthostatic tachycardia syndrome (POTS): A systematic review and meta-analysis
The conditions most often mentioned are Hashimoto’s thyroiditis, lupus, Sjögren’s, rheumatoid arthritis, and celiac disease. Joint swelling, dry eyes and mouth, or rashes deserve a mention to your doctor, as does persistent gut trouble after eating gluten. Treating a coexisting condition may improve your overall energy.
An ANA test looks for antibodies that react to the contents of your cells, and doctors often use it as a first screen when they suspect autoimmune disease. A positive ANA alone is common in healthy people and doesn’t mean you have a disease. A positive ANA test in someone with POTS and no other signs most often leads to watching and reassessing, not treatment.
Infections, COVID, and Vaccines as Triggers
A viral infection precedes POTS in about 28% to 41% of patients.25PubMed Central. Postural orthostatic tachycardia syndrome and post-acute COVID-19 Linked infections include Epstein-Barr virus, respiratory and stomach bugs, and COVID.26PubMed Central. Postural orthostatic tachycardia syndrome and post-acute COVID-19 Other reported triggers include vaccination, pregnancy, surgery, and trauma.27PubMed Central. Postural orthostatic tachycardia syndrome and post-acute COVID-19 Long COVID and POTS share some of the same autoantibodies,28PubMed Central. Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID so an infection may push the immune system into attacking the body’s own nerve signals. Immune messenger patterns were similar in POTS that began after COVID and POTS before the pandemic.29PubMed Central. Plasma Cytokine and Caspase-1p20 Profiles in Pre-Pandemic and Long COVID-Associated Postural Orthostatic Tachycardia Syndrome
A post-viral start usually shows up days to weeks after the illness. The racing heart and exhaustion linger after the fever ends.
Most people recover from the same infections without lasting symptoms, so the infection alone isn’t the full explanation. Researchers think a person’s own immune response, and possibly an existing tendency, may decide whether the nervous system settles back to normal.
Vaccines are listed as a reported trigger, but infections are far more common ones, and the illness a vaccine prevents can itself trigger POTS. If a prior shot worsened your symptoms, discuss timing with your doctor.
Immune Testing and Treatments
There is no reliable blood marker for POTS, which contributes to long diagnosis delays.30PubMed. Quantitative serum proteomic analysis for biomarker discovery in post-COVID-19 postural orthostatic tachycardia syndrome (PC-POTS) patients Diagnosis still relies on heart rate changes when standing or on a tilt-table test. A stand test records heart rate and blood pressure lying down and then at set times standing, often over about ten minutes. POTS is generally diagnosed when heart rate rises by a sustained amount on standing without a big blood pressure drop, alongside symptoms lasting months. A tilt-table test does the same on a table that tips you upright, in a controlled setting. Preparation such as fluids and medication timing can change results, so follow the instructions you’re given.
Receptor autoantibody tests exist mainly through specialty labs and aren’t used to diagnose POTS. If you have matching symptoms, ask about ANA, thyroid, celiac, and mast cell tests.
IVIG is an infusion of donated antibodies that can calm a misdirected immune response. In a small controlled trial, it did no better than a placebo-like albumin infusion.31PubMed. Randomized controlled trial of intravenous immunoglobulin for autoimmune postural orthostatic tachycardia syndrome (iSTAND) Yet in small groups of severe patients, IVIG cut symptom severity by nearly 40% after 6 months.32PubMed. Immunomodulatory treatment in postural tachycardia syndrome: A case series In seven patients given antibody injections or plasma exchange, all improved and five returned to work or school.33PubMed. Immunotherapy with subcutaneous immunoglobulin or plasmapheresis in patients with postural orthostatic tachycardia syndrome (POTS) Results are promising in selected cases but uncertain overall. Gentle electrical stimulation of the vagus nerve through the ear for 1 hour daily lowered an inflammation marker over 2 months.34PubMed Central. Noninvasive Vagus Nerve Stimulation in Postural Tachycardia Syndrome
Immune therapy is usually considered for people with severe POTS that resists standard care, often those with clear autoimmune markers or diseases, and it’s given at specialist autonomic centers. Insurance often won’t cover it for POTS alone.
Fluids, salt, compression, and gradual exercise help regardless of immune cause. Be cautious with clinics selling unproven immune or gut cures.
What This Means for Your Day-to-Day Health
Because infections can trigger POTS, colds and stomach bugs often cause temporary flares. During illness, drink more than usual, using fluids with electrolytes if you can, because fever and sweating cost fluid. Add extra salt and rest more. If you vomit or have diarrhea and can’t keep fluids down, contact your doctor, since dehydration can worsen symptoms and sometimes needs fluids through a vein. Lie down or sit when symptoms spike rather than pushing through, and return to activity gradually as you recover instead of resuming your normal level in one day.
Keep a symptom diary noting infections, foods, heat, and cycle days. Seek prompt care for new joint swelling, rashes, or numbness, which may signal a coexisting condition.
At appointments, bring the dates of any illness that started your symptoms and a list of allergy-like and autoimmune symptoms. Ask which tests fit your symptoms, and whether a referral to an autonomic specialist makes sense. Many people with post-viral POTS improve over months to years.