Testing for hEDS, POTS and MCAS: what's real and what isn't
Is there a test for hypermobile EDS?
2017 hEDS clinical criteria (including the Beighton score)
Guideline-backedWhat it can tell you
Whether you meet the current formal criteria, based on a physical exam and history.
What it can't tell you
How severe things are or how to manage them. Hypermobility spectrum disorder (HSD) can be just as disabling and needs the same care.
Source: Source 1
A genetic test "for hEDS"
Not validated / not recommendedWhat it can tell you
Nothing — the Ehlers-Danlos Society states there is no genetic test for hEDS yet. Direct-to-consumer DNA tests don't diagnose it either.
Source: Source 2
Targeted genetic testing for other EDS types
Useful in specific situationsWhat it can tell you
Confirms or rules out types that do have known genes, such as vascular or classical EDS, when features suggest them.
What it can't tell you
hEDS. Gene panels can also return "variants of uncertain significance" that don't answer anything.
Source: Source 1
Echocardiogram
Useful in specific situationsWhat it can tell you
Mitral valve prolapse or aortic root enlargement, which count toward the 2017 criteria.
What it can't tell you
Much as a routine screen — in a 2024 study these findings were uncommon in hEDS and HSD (aortic root enlargement in 2.7% of hEDS, mitral valve prolapse in 3.5%).
Source: Source 3
How is POTS diagnosed?
10-minute active stand test or tilt table test
Guideline-backedWhat it can tell you
POTS, when heart rate rises by 30 bpm or more within 10 minutes of standing (40 or more in ages 12–19), without a significant blood pressure drop, alongside ongoing symptoms.
What it can't tell you
The underlying cause. Dehydration, deconditioning and some medications can affect results.
Source: Source 4
ECG, blood count, thyroid tests
Guideline-backedWhat it can tell you
Rules out heart rhythm problems, anemia and an overactive thyroid that can mimic POTS.
What it can't tell you
Whether you have POTS.
Source: Source 4
Ferritin
Limited evidenceWhat it can tell you
Low iron stores, which may worsen symptoms. One small study of 24 teenagers with POTS found low ferritin in half.
What it can't tell you
Whether you have POTS.
Source: Source 5
Standing norepinephrine
Useful in specific situationsWhat it can tell you
A "hyperadrenergic" pattern, which may influence treatment choice.
What it can't tell you
Whether you have POTS. Results are very sensitive to how the blood is drawn.
Autonomic testing or skin biopsy for small fiber neuropathy
Useful in specific situationsWhat it can tell you
Nerve involvement in some people with POTS — in one study, 9 of 24 met criteria for a "neuropathic" pattern.
What it can't tell you
It isn't needed to diagnose POTS and doesn't yet change standard treatment.
Source: Source 6
Commercial "POTS antibody" panels (adrenergic and muscarinic receptor antibodies)
Not validated / not recommendedWhat it can tell you
Nothing reliable. In a 2022 study of 116 people with POTS and 81 healthy controls, results didn't differ for any antibody — the alpha-1 adrenergic antibody was "positive" in 98% of POTS patients and 100% of controls.
Source: Source 7
How is MCAS diagnosed?
Consensus definitions require three things: typical episodic symptoms in at least two body systems, a lab-documented rise in a mast cell mediator during an episode, and a response to mast-cell-targeted treatment. A symptom checklist alone isn't enough under these definitions. [Source 8]
Paired tryptase (during an episode and at baseline)
Guideline-backedWhat it can tell you
Mast cell activation, if tryptase during an episode rises above 120% of your baseline plus 2 ng/mL. It's best drawn 30–120 minutes after symptoms start, with the baseline taken at least 24 hours after symptoms settle. It can still be measured up to about 4 hours after symptoms start.
What it can't tell you
A single normal result doesn't rule MCAS out.
Source: Source 8, 9
Urine mediators (N-methylhistamine, 11β-prostaglandin F2α, leukotriene E4)
Useful in specific situationsWhat it can tell you
Supporting evidence when levels rise during symptoms.
What it can't tell you
Much alone — collection and handling affect results, and the US allergy work group found N-methylhistamine of little use on its own.
Source: Source 8
Hereditary alpha-tryptasemia (HαT) gene test
Useful in specific situationsWhat it can tell you
Explains most cases of a raised baseline tryptase; considered when baseline tryptase is above 8 ng/mL with relevant symptoms.
What it can't tell you
Whether you have MCAS — most people with HαT are healthy.
Source: Source 9
Plasma histamine, chromogranin A, heparin
Not validated / not recommendedWhat it can tell you
Nothing reliable for MCAS. Chromogranin A isn't a mast cell marker at all.
Source: Source 8
What sources does this page use?
- Malfait F, et al. The 2017 international classification of the Ehlers–Danlos syndromes. Am J Med Genet C Semin Med Genet. 2017;175(1):8–26.
- The Ehlers-Danlos Society. Myths and facts about EDS and HSD. https://www.ehlers-danlos.com/myths-and-facts-about-eds-and-hsd/
- Knight DRT, Bruno KA, Singh A, et al. Cardiac defects of hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders: a retrospective cohort study. Front Cardiovasc Med. 2024;11:1332508. doi:10.3389/fcvm.2024.1332508
- Sheldon RS, et al. 2015 Heart Rhythm Society expert consensus statement on POTS, IST and VVS. Heart Rhythm. 2015;12(6):e41–e63.
- Jarjour IT, Jarjour LK. Low iron storage and mild anemia in postural tachycardia syndrome in adolescents. Clin Auton Res. 2013;23(4):175–179. doi:10.1007/s10286-013-0198-6
- Gibbons CH, Bonyhay I, Benson A, Wang N, Freeman R. Structural and functional small fiber abnormalities in the neuropathic postural tachycardia syndrome. PLoS One. 2013;8(12):e84716.
- Hall J, Bourne KM, Vernino S, et al. Detection of G protein–coupled receptor autoantibodies in postural orthostatic tachycardia syndrome using standard methodology. Circulation. 2022;146(8):613–622. doi:10.1161/CIRCULATIONAHA.122.059971
- Weiler CR, et al. AAAAI Mast Cell Disorders Committee Work Group report: mast cell activation syndrome. J Allergy Clin Immunol. 2019;144(4):883–896.
- Beyens M, Toscano A, Ebo D, Gülen T, Sabato V. Diagnostic significance of tryptase for suspected mast cell disorders. Diagnostics (Basel). 2023;13(24):3662.
How should I cite this page?
Niehaus L. Testing for hEDS, POTS and MCAS: what's real and what isn't. The Lily Perspective. Published October 2026. Updated October 2026. https://lilyperspective.com/toolkit/lab-tests/hypermobility-pots-mcas
© 2026 Lily Niehaus. All rights reserved. You're welcome to link to this page or quote short passages with credit to The Lily Perspective.