Hypermobility, POTS, and Blood Pooling: What the 2026 Research Actually Found
If you are hypermobile and the room tilts every time you stand up, you have probably been handed the same three-line prescription more than once. Drink more water. Add salt. Wear compression socks. Somewhere along the way, someone probably suggested anxiety.
What almost nobody explains is where the blood is actually going when you stand — and why, in a hypermobile body, it may not behave the way the textbook says it should. Three papers published in 2026 sharpen that picture considerably. One of them also complicates it, in a way you deserve to hear about before anyone puts you through an expensive workup.
What blood pooling actually means
When you stand up, gravity pulls a significant volume of blood downward into your legs, pelvis, and abdomen. In most people, the veins tighten, the calf muscles squeeze, and blood returns to the heart quickly enough that nothing noticeable happens. If that return is slow or incomplete, the heart has less blood to work with and compensates by beating faster.
That is the mechanism behind postural orthostatic tachycardia syndrome (POTS). The racing heart is the compensation, not the problem itself — which is why treatments aimed only at slowing the heart rate so often disappoint.
Connective tissue is what gives veins their springiness. In hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorder (HSD), connective tissue behaves differently throughout the body, not only in the joints that bend further than they should. That has long been the working theory for why hypermobility and orthostatic intolerance travel together so often.
The 2026 finding: it may not only be stretchy veins
A study published in Phlebology in 2026 looked at this from an angle most patients have never heard discussed. Instead of asking whether hypermobile veins are too elastic, the researchers asked whether they are being physically squeezed.
The team reviewed contrast-enhanced abdominal and pelvic CT scans from 109 people — 25 with hEDS, 64 with HSD, and 20 controls — and measured compression of the left common iliac vein, the large vein that drains the left leg and pelvis. They counted narrowing of more than 50 percent as significant.
Significant compression showed up in 68.0 percent of the hEDS group, 65.6 percent of the HSD group, and 35.0 percent of controls. The odds of significant compression were roughly four times higher in both hypermobility groups than in controls (odds ratio 3.95 for hEDS, 3.54 for HSD). There was no meaningful difference between the hEDS and HSD groups.
A systematic review published the same year in Vascular Health and Risk Management points in a similar direction. Reviewing the literature on abdominopelvic vascular compression syndromes in EDS and HSD, the authors report that POTS appears in up to 50 percent of patients with EDS or HSD, that 69 percent of patients with POTS in the studies reviewed had significant left common iliac vein compression, and that 77 percent had compression of the iliac vein, the renal vein, or both.
The part most articles leave out
Here is where honest reporting matters more than good marketing.
A 2026 review in Biomedicines examined the same family of vascular compression syndromes and their relationship to autonomic dysfunction, and its conclusion is deliberately restrained. The authors note that similar gradients and stenoses have been observed in patients with no symptoms at all, and that it is unclear why some people with the same degree of narrowing feel nothing. They state plainly that high-quality prospective data remain limited and that prospective studies are still needed to establish whether these relationships are causal.
The Vascular Health and Risk Management review is equally candid about the thinness of the evidence base: of 183 studies screened, 62 met inclusion criteria, and only six directly addressed vascular compression syndromes in EDS or HSD. The authors describe tailored diagnostic and treatment algorithms as lacking.
So the fair summary is this. Vein compression is clearly more common in hypermobile bodies. Whether it is causing a given person’s symptoms is a separate question that an image alone cannot answer.
Why the internet disagrees about this
If you have spent an evening reading about pelvic vein compression and POTS, you have probably found two camps that seem to be describing different universes. One presents compression as the overlooked answer nobody is testing for. The other dismisses it as an incidental finding.
Both are reading real data. The disagreement is not about the pictures — it is about what the pictures mean, and that question has not been settled by the research that exists today.
Which is exactly why the interesting question for a patient is not does this exist but does this explain me.
What to ask a provider
If you are hypermobile and struggling with orthostatic symptoms, these questions tend to move a visit forward:
- Has anyone actually measured what my heart rate and blood pressure do over ten minutes of standing, rather than checking them once while I sit?
- Are my symptoms worse in the afternoon, after meals, in heat, or after prolonged standing — and does that pattern fit pooling?
- Do I have symptoms that point specifically toward the abdomen and pelvis, such as flank pain, pain after eating, or pelvic heaviness, rather than lightheadedness alone?
- If imaging is being suggested, what decision would change based on the result?
- What are we trying first that does not involve a procedure?
That last question matters. The systematic review describes invasive imaging and intervention as generally appearing safe in EDS and HSD — with the important exception of vascular EDS, where catheter-based procedures with injected contrast are generally discouraged because of the risk of arterial tears or dissection. But safety is not the same as benefit, and the review is explicit that robust outcome data are lacking.
Who is generally not a good candidate for this line of investigation
We would rather tell you this now than after a workup.
If your standing symptoms have never been objectively documented, imaging is premature. The first step is measuring what your body actually does upright, not photographing your veins.
If you have vascular EDS specifically, this conversation changes significantly and belongs with a specialist familiar with that diagnosis. It is a different condition with different risks, and the cautions above apply directly.
If your symptoms are better explained by something already on the table — anemia, thyroid disease, medication side effects, deconditioning after an illness, dehydration from a gut condition — that should be addressed before anyone goes looking for a rarer explanation.
And if you are hoping a scan will produce a single fixable cause, the current evidence does not support that expectation.
Venturis Clinic does not perform vascular stenting or vascular surgery. If an evaluation suggests a structural vascular problem needs interventional assessment, the right next step is a vascular specialist, and we will say so.
How we think about this at Venturis Clinic
Venturis founder Dr. Alvin Philipose spent over 25 years in regenerative and functional medicine in Oklahoma City, much of it with patients whose testing keeps coming back normal while their lives keep getting smaller.
For hypermobility and orthostatic intolerance, our starting point is characterization rather than procedure. What do your vitals do upright. What is your fluid and electrolyte status. What is the pattern of your worst hours. Where does your joint instability sit, and is it contributing to the deconditioning cycle that makes standing harder. Candidates for any therapy are evaluated individually during a consultation, and results vary.
Our POTS integrative treatment approach is built around that kind of characterization. For the joint instability side of hypermobility, our article on prolotherapy for hypermobile Ehlers-Danlos syndrome covers what that involves. And if you are trying to make sense of how several diagnoses fit together, the MCAS, POTS, and EDS triad is a useful place to start.
Frequently asked questions
Does hypermobility cause POTS?
The two occur together far more often than chance would predict, and the systematic review discussed above reports POTS in up to 50 percent of patients with EDS or HSD. Whether hypermobility causes POTS, shares a cause with it, or simply travels alongside it has not been established.
What is May-Thurner syndrome, and how is it related?
May-Thurner syndrome is compression of the left iliac vein, usually where an overlying artery crosses it. It is one of several abdominopelvic vascular compression syndromes, along with nutcracker syndrome, median arcuate ligament syndrome, and superior mesenteric artery syndrome. The 2026 research found this type of compression to be considerably more common in hypermobile patients.
Why do my symptoms get worse after eating?
Digestion redirects blood flow to the gut, which reduces the volume available to return to the heart when you stand. Post-meal worsening is a common pattern in orthostatic intolerance and is worth mentioning to your provider, because it helps distinguish pooling-related symptoms from other causes.
Should I get a CT scan to look for vein compression?
That is a decision for you and a physician who has examined you, not something a website can answer. The research suggests compression findings are common in hypermobile people, including some who have no symptoms — so the value of imaging depends heavily on what specific question it is being asked to answer.
Do compression garments actually help?
Many patients report that they do, and they are a low-risk thing to try. The mechanism discussed here is one reason clinicians increasingly pay attention to abdominal and pelvic support rather than leg coverage alone. Individual response varies.
Is this the same thing as being told my symptoms are anxiety?
No. Orthostatic intolerance produces measurable changes in heart rate and blood pressure on standing. Those changes can be documented. If a full standing evaluation has not been performed, the question has not actually been asked yet.
Can IV fluids or nutrient therapy fix this?
No single infusion resolves POTS or hypermobility, and we will not suggest otherwise. Some patients explore intravenous support as one part of a broader plan intended to support hydration and nutrient status; whether it is appropriate is evaluated during a consultation, and results vary.
Do you treat patients from outside Oklahoma City?
Yes. We see patients from across the OKC metro, including Edmond, Norman, Moore, Yukon, Mustang, and Nichols Hills, as well as patients who travel from elsewhere in Oklahoma.
Talk with us
If standing up is the hardest part of your day and no one has explained why, a conversation is a reasonable next step. We offer a free 15-minute phone consultation.
Venturis Clinic
7917 N May Ave, Suite B
Oklahoma City, OK 73120
(405) 848-7246
Sources
- Ogunlade SB, Brown D, Rozen T, Lewis AR, Toskich BB, Fairweather D, Bruno KA, Knight D, Devcic Z. Comparative assessment of left common iliac vein compression in patients with hypermobile Ehlers-Danlos syndrome, hypermobility spectrum disorder and healthy controls — a retrospective single-centre study. Phlebology. 2026;41(6):506–514. DOI: 10.1177/02683555251400392
- Bruessel P, Govender M, Frahm-Jensen G. The Investigation and Management of the Abdominopelvic Vascular Compression Syndromes in Patients with Ehlers-Danlos Syndrome and Hypermobility Spectrum Disorder. Vascular Health and Risk Management. 2026;22:1–15. DOI: 10.2147/VHRM.S592420
- Davis BM, Rantanen P, Seo G, Thadani S, Spencer EB, Hepworth E, Cutchins A. An Overview of Vascular Compression Syndromes and Associations with Autonomic Dysfunction: A Review. Biomedicines. 2026;14(3):689. DOI: 10.3390/biomedicines14030689
Disclaimer
This content is for educational purposes only and is not medical advice, diagnosis, or treatment. Individual results vary and no outcome is guaranteed. Venturis Clinic offers regenerative, functional, and alternative medicine services; some therapies discussed are not FDA-approved for the uses described. Talk with a qualified healthcare provider about your specific situation before beginning any treatment.
