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Dr. Alessandro Giardini
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Some children arrive at a PoTS assessment and mention almost in passing that they have always been very flexible. They can put their palms flat on the floor, bend their thumbs back to their wrists, or hyperextend their elbows and knees in ways their friends cannot. Nobody has told them this is medically significant. Often it is not. But in a child with PoTS, that flexibility is worth a careful look.
Joint hypermobility and postural tachycardia syndrome occur together far more often than chance would predict. Understanding why they are connected, what it means for the clinical picture, and how it changes the approach to treatment is genuinely useful for families navigating both diagnoses at once.
The connection lies in connective tissue. Connective tissue is the structural scaffolding of the body: it holds joints together, gives skin its elasticity, and forms the walls of blood vessels. In hypermobility spectrum disorder (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS), this connective tissue is more lax and extensible than normal. The result is joints that move beyond their typical range of motion and, importantly, blood vessel walls that distend more easily than they should.
That vascular laxity has direct cardiovascular consequences. When a child with hypermobility stands up, the blood vessels in the lower limbs, already structurally more compliant than average, allow blood to pool in the legs more extensively than in a child with normal connective tissue tone. The autonomic nervous system attempts to compensate by raising the heart rate. That compensatory tachycardia is PoTS.
Research estimates suggest that between 25% and 60% of children with PoTS also meet criteria for joint hypermobility or hEDS, depending on the population studied and the diagnostic criteria used. The reverse relationship is similarly striking: a high proportion of patients with confirmed hEDS show signs of autonomic dysfunction, with PoTS being the most commonly identified pattern.
This is not coincidence. It is the same biological substrate producing two sets of symptoms through two different but related mechanisms.
A child with both hypermobility and PoTS often presents with a symptom burden that is heavier than either condition alone would produce. Chronic musculoskeletal pain from unstable joints compounds the fatigue of PoTS. Poor sleep from joint discomfort reduces the overnight cardiovascular recovery that PoTS already disrupts. Gut dysmotility, which is common in hEDS due to connective tissue laxity in the gut wall, adds nausea and bloating to the cardiovascular symptoms.
Dr Giardini assesses for possible hypermobility all children presenting with suspect PoTS at the initial assessment and when required refers to appropriate rheumatology and physio colleagues. The finding of significant hypermobility changes the prognosis and changes the treatment approach in specific ways, and missing it means a child with hEDS receives only partial management.
The diagnosis of hEDS itself is clinical. There is no genetic test for the hypermobile subtype, and confirming it typically involves a detailed assessment of joint mobility, skin, family history, and associated features by a specialist with experience in connective tissue disorders. Dr Giardini coordinates onward referral to relevant specialists where this assessment is needed.
The core PoTS treatment approach, described in the full condition guide, applies to all children regardless of whether hypermobility is present. Fluid and salt supplementation, compression garments, and graded exercise reconditioning are all relevant. The presence of hEDS, however, adds important layers.
Exercise programming requires adaptation. The graded exercise approach for PoTS starts with recumbent activity and builds progressively toward upright exercise. In a child with significant joint hypermobility, certain exercises carry a higher injury risk because unstable joints are more vulnerable to strain. Swimming is particularly well suited because it provides cardiovascular reconditioning without loading hypermobile joints in vulnerable positions. Resistance work aimed at building the muscle tone that compensates for lax ligaments is valuable but needs to be designed with the hypermobility in mind, not borrowed from a standard PoTS programme.
Physiotherapy, when available from someone experienced in hypermobility, should run alongside the cardiovascular reconditioning. The goal is strengthening the muscle envelope around unstable joints, improving proprioception, and reducing the pain that otherwise limits activity participation.
Compression garments are particularly effective in children with both conditions, because they counteract the venous pooling driven by vascular laxity as well as providing some proprioceptive support to hypermobile joints.
The prognosis for PoTS in the setting of hEDS is generally more guarded than for post-viral PoTS in a child with normal connective tissue. Because the underlying vascular laxity does not resolve with time in the way that post-viral autonomic dysregulation sometimes does, the management tends to be longer-term and the realistic goal is consistently good symptom control and maintained function rather than complete resolution.
One of the more complex clinical situations in paediatric cardiology is a teenager who appears to have PoTS, significant hypermobility, and profound fatigue that does not respond well to the usual PoTS measures. This triad sometimes represents a third overlapping condition: ME/CFS. The symptom overlap between these three conditions is substantial, and distinguishing them requires careful evaluation. The dedicated page on PoTS and ME/CFS addresses this in detail, because the treatment implications are different and getting the clinical picture right matters considerably.
A child with both PoTS and hypermobility often faces a double challenge in the school environment. The cardiovascular symptoms make standing and sustained concentration difficult. The joint symptoms make sitting on hard chairs for long periods painful and make PE activities that involve jumping, impact, or rapid direction change potentially harmful. It is important to let the school know about the challenges faced, helping schools understand that the restrictions are not precautionary excess but reflect two distinct and related conditions that both require accommodation.
No. Many children with joint hypermobility never develop PoTS. The association is real and statistically significant, but hypermobility is common and PoTS is not present in every hypermobile child. PoTS develops when the cardiovascular autonomic system fails to compensate adequately for the postural change in blood distribution. Not every hypermobile child reaches that threshold.
Not in general. The right answer depends on the sport, the degree of hypermobility, and the current severity of PoTS symptoms. High-impact, collision, or overhead sports carry more joint risk in hypermobile children. Swimming and cycling, which are also excellent for PoTS reconditioning, are generally well tolerated.
The assessment for hEDS is typically done by a clinical geneticist, a rheumatologist with specialist interest in connective tissue disorders, or in some centres a specialist hypermobility physiotherapist. Dr Giardini can advise on the most appropriate referral pathway from London and will include a summary of the cardiovascular findings to inform that assessment.
Author: Dr. Alessandro Giardini, MD, PhD, Consultant Paediatric Cardiologist
Written 11/06/2026