There is a protein inside you called collagen. You have heard of it in the context of skincare advertising — the promise that some cream or supplement will restore the collagen that youth has taken away. But collagen is not primarily a cosmetic substance. It is the structural foundation of the human body. Accounting for roughly one-third of total protein mass, collagen forms the fibrous architecture of tendons, ligaments, cartilage, bone, skin, blood vessel walls, the gut, the cornea, and the connective tissue planes that hold every organ in its anatomical position. There are at least twenty-eight distinct collagen types, encoded by different genes, performing different structural functions in different tissues. When the genes that encode collagen — or the enzymes that process, cleave, hydroxylate, or cross-link it — are defective, the consequences are not local. They are systemic. Every structure in the body built from collagen is affected. Every organ that depends on connective tissue support — which is every organ — is, to some degree, compromised. This is Ehlers-Danlos Syndrome. Not one disease, but a family of at least thirteen heritable connective tissue disorders, united by their common molecular substrate and their common experience: years, sometimes decades, of being told by medicine that the problem is anxiety, deconditioning, a low pain threshold, or a desire for attention — while the scaffolding of the body quietly, structurally, irreversibly comes undone.

The name Ehlers-Danlos comes from two dermatologists — Edvard Ehlers of Denmark and Henri-Alexandre Danlos of France — who published case reports in the early twentieth century describing patients with hyperextensible skin and hypermobile joints. Their observations were sound. Their framing was incomplete. EDS is not primarily a skin condition. It is not primarily a joint condition. It is a disease of connective tissue — which means it is, in the most literal anatomical sense, a disease of the body's ability to hold itself together. The skin hyperextensibility and joint hypermobility that gave the condition its initial definition are the visible surface of a much deeper and more consequential pathology. Below the skin and beyond the joints lies a catalogue of complications — cardiovascular, neurological, autonomic, gastrointestinal, immunological — that the original observers could not have appreciated, and that modern medicine has been slow to recognise as the expressions of a single underlying disorder.

The full catalogue of what EDS does to the people who have it is the subject of this article. But before the catalogue, a statement about scale. Conservative estimates place the prevalence of hypermobile EDS — the most common subtype — at approximately one in five hundred individuals, making it one of the most common heritable connective tissue disorders on earth. More recent epidemiological estimates suggest the true prevalence may be substantially higher, once diagnostic delay and misclassification are accounted for. Against this prevalence, the average diagnostic delay in adult patients is between ten and twenty years — years during which the joints are accumulating damage that appropriate management could have slowed, years during which the autonomic nervous system is deteriorating without the stabilising treatment that exists, years during which the patient is being told, with clinical confidence, that what is happening to their body is not happening.

The Molecular Basis

The Biology — What Goes Wrong and Why

EDS is caused by mutations in genes encoding collagen itself, the enzymes that process and modify collagen, or the structural proteins that work alongside collagen in the extracellular matrix. Different subtypes are caused by mutations in different genes, which is why different subtypes have different clinical profiles and different inheritance patterns. Understanding the molecular basis matters clinically because it determines prognosis, guides management decisions, and, for the dangerous subtypes, has direct implications for surgical risk and life expectancy.

The key concept is that collagen dysfunction produces tissue fragility and abnormal compliance — in proportions that vary by collagen type affected and by the nature of the mutation. In the classical and vascular subtypes, where specific collagen genes are mutated, the tissue fragility is severe and measurable. Skin tears under minimal trauma. Blood vessels rupture spontaneously. Wounds fail to heal because the fibrous architecture they need to close is structurally abnormal. In hypermobile EDS — by far the most prevalent subtype — the genetic basis remains, as of 2026, only partially characterised. The structural defect is real and heritable, but it expresses less as dramatic fragility and more as a pervasive loss of tissue compliance and stability: joints that move too far in every direction; ligaments that cannot hold structures in position; autonomic nerves that cannot maintain vascular tone; mast cells that fire on inappropriate triggers; a spinal cord that is pulled by a filum terminale that has traded its elasticity for fibrous stiffness.

What connects the subtypes is the extracellular matrix — the biological scaffolding that surrounds every cell in the body and gives tissues their mechanical properties. When the components of that matrix are defective, the properties change: tissues become either too stiff or too lax, often simultaneously in different anatomical compartments. The result is a body that is simultaneously too flexible where it should be stable, and too rigid where it should be compliant — a paradox that takes clinicians years to understand and that patients live inside every hour of every day.

The Thirteen Types

The EDS Subtypes — Thirteen Conditions, One Root

The 2017 International Classification of Ehlers-Danlos Syndromes, published in the American Journal of Medical Genetics, delineated thirteen subtypes, each with specific diagnostic criteria, inheritance patterns, and — for twelve of the thirteen — identified causative genes. Understanding which subtype a patient has is clinically critical: the management, monitoring requirements, surgical risk, and prognosis differ substantially between subtypes.

Most Common · Prevalence ~1 in 500

Hypermobile EDS (hEDS)

The most prevalent and most diagnostically challenging subtype. Causative gene(s) not yet fully identified — diagnosis remains clinical, based on the 2017 criteria. Characterised by generalised joint hypermobility, joint instability with recurrent subluxations and dislocations, chronic musculoskeletal pain, soft-tissue injury, and a high burden of systemic comorbidities including POTS, MCAS, gastrointestinal dysmotility, and neurological complications. The absence of a genetic test makes diagnosis entirely dependent on clinical recognition — which is simultaneously the reason for extraordinary diagnostic delay and the reason hEDS advocates most urgently need clinicians who understand it. Autosomal dominant inheritance pattern is observed empirically, though the gene(s) are not yet confirmed.

Rare · Life-Threatening Complications

Vascular EDS (vEDS)

Caused by mutations in COL3A1, encoding type III collagen. The most clinically dangerous subtype. Type III collagen is the primary structural component of blood vessel walls and hollow viscera; its deficiency produces extreme fragility of medium-sized arteries, the bowel wall, and the uterus. Spontaneous arterial rupture — classically the celiac, superior mesenteric, renal, or iliac arteries — is the most feared complication and may be the presenting event. Bowel perforation and uterine rupture in pregnancy also occur. Median survival in historical cohorts was 48 years, though contemporary management with celiprolol (a cardioselective beta-blocker with vasodilatory properties shown in RCT to reduce arterial events in vEDS) has improved outcomes. Skin is characteristically thin and translucent with visible venous patterning, but hypermobility is typically limited to the small joints. Autosomal dominant. Genetic testing is essential for diagnosis and family screening.

Uncommon · Significant Morbidity

Classical EDS (cEDS)

Caused by mutations in COL5A1 or COL5A2, encoding type V collagen. Characterised by marked skin hyperextensibility, atrophic scarring (the classic "cigarette-paper" scars at pressure points and over bony prominences), generalised joint hypermobility, and easy bruising. The skin in cEDS is dramatically extensible — often described as velvet-like in texture — and wounds heal with characteristic widened, thinned scars that are diagnostic hallmarks. Subcutaneous molluscoid pseudotumours (fatty lumps over pressure points) and spheroids (calcified nodules beneath the skin of the shins and forearms) are specific examination findings. Autosomal dominant in most cases; autosomal recessive variants described. Generally better prognosis than vEDS; major vascular involvement is uncommon but not absent.

Rare · Progressive Deformity

Kyphoscoliotic EDS (kEDS)

Caused by mutations in PLOD1 (encoding lysyl hydroxylase 1) or FKBP14. Autosomal recessive. Characterised by congenital or early-onset progressive scoliosis, severe generalised muscle hypotonia at birth, joint hypermobility, and skin fragility. The scoliosis is a dominant clinical feature and the source of the condition's name. Ocular fragility — with risk of globe rupture — is an important feature in the PLOD1 variant. Without diagnosis and appropriate orthopaedic and respiratory surveillance, progressive scoliosis may result in severe cardiorespiratory compromise. The muscle hypotonia may be profound enough at birth to cause diagnostic confusion with primary neuromuscular disorders. Urinary lysyl pyridinoline:hydroxylysyl pyridinoline ratio is an accessible and sensitive biochemical marker for the PLOD1 variant.

Rare

Arthrochalasia EDS (aEDS)

Caused by mutations in COL1A1 or COL1A2 affecting the N-propeptide cleavage site of type I procollagen. Autosomal dominant. Characterised by congenital bilateral hip dislocation (present at birth — a near-universal feature that should raise clinical suspicion), severe generalised joint hypermobility with multiple dislocations, skin hyperextensibility, and moderate skin fragility. The hip dislocation at birth is the key diagnostic indicator; in the absence of a genetic explanation, all infants with congenital hip dislocation should be considered for EDS evaluation. Progressive joint deformity and recurrent dislocations are the major long-term morbidities.

Rare

Dermatosparaxis EDS (dEDS)

Caused by mutations in ADAMTS2, encoding the enzyme that cleaves the N-propeptide from procollagens I, II, and III. Autosomal recessive. Produces extreme skin fragility — the skin tears under minimal mechanical stress and has a characteristic sagging, redundant appearance with pachygyria-like features. Severe bruising, premature rupture of membranes in pregnancy, and hernias are common. Joint hypermobility is typically mild. Facial features are characteristic: puffy eyelids, epicanthal folds, and a distinctive aged or wrinkled appearance of the skin. Rare; fewer than 200 cases reported in the literature as of 2024.

Rare · Corneal Involvement

Brittle Cornea Syndrome (BCS-EDS)

Caused by mutations in ZNF469 or PRDM5. Autosomal recessive. The defining feature is extreme corneal thinning with very high risk of spontaneous corneal rupture — the cornea may perforate under minimal trauma or even spontaneously. Blue sclerae, mild sensorineural hearing loss, joint hypermobility, and mild skin hyperextensibility are associated features. Ophthalmological management and protective eyewear are lifesaving. All patients require urgent ophthalmology referral and lifelong corneal monitoring.

Rare · Musculocontractural

Classical-Like EDS (clEDS) & Other Rare Subtypes

Classical-like EDS is caused by mutations in TNXB (tenascin XB), producing a clinical picture similar to classical EDS but without atrophic scarring and with progressive joint instability. Additional rare subtypes include Musculocontractural EDS (CHST14, DSE), Myopathic EDS (COL12A1), Periodontal EDS (C1R, C1S), Spondylodysplastic EDS (B4GALT7, B3GALT6, SLC39A13), and Cardiac-valvular EDS (COL1A2). Each has a specific molecular basis, specific clinical features, and specific management implications. Genetic testing panels now available at specialist centres can screen for all known causative genes simultaneously.

"I had my first dislocation at age seven. I was told I was 'double-jointed' and that this was a party trick. By twenty-five I had dislocated my shoulder forty-three times, my kneecap sixteen times, and my jaw twice. I was told I had a high pain tolerance and poor proprioception. Nobody used the word collagen. Nobody used the words Ehlers-Danlos. I found them myself, in a research article, at two in the morning, after eleven years of appointments."

The Diagnostic Framework

Diagnosing EDS — The Criteria, the Tools, and the Systemic Failures

For twelve of the thirteen EDS subtypes, diagnosis is confirmed by molecular genetic testing identifying a pathogenic variant in the relevant gene. For hypermobile EDS — the most prevalent subtype — there is no confirmatory genetic test. The 2017 International Classification provides detailed clinical diagnostic criteria that must be satisfied, combining major and minor criteria across three domains. Understanding these criteria is important for patients navigating the diagnostic process, because the criteria exist, are published, and are available — yet the majority of EDS diagnoses are still made by specialists who found the condition themselves rather than by the generalists who saw the patient first.

The Beighton Score — Hypermobility in Nine Points

The Beighton Score is the most widely used clinical tool for documenting generalised joint hypermobility. It assesses mobility at five sites on a nine-point scale. A score of five or more (out of nine) in adults under fifty, or four or more in adults over fifty, or three or more in children, indicates generalised joint hypermobility in the context of EDS diagnosis. Crucially, the Beighton Score is a screening tool, not a diagnostic criterion in isolation — many hypermobile individuals do not have EDS, and some EDS patients lose hypermobility over time due to joint damage, acquired stiffness, or ageing.

Joint / Movement What Is Assessed Points
Fifth finger passive dorsiflexion ≥90° Passive extension of the little finger beyond 90°, assessed bilaterally 1 per side (max 2)
Thumb passive apposition to forearm Passive opposition of the thumb to touch the flexor aspect of the forearm, bilaterally 1 per side (max 2)
Elbow hyperextension ≥10° Elbow extension beyond 10°, assessed bilaterally 1 per side (max 2)
Knee hyperextension ≥10° Knee extension beyond 10° (genu recurvatum), assessed bilaterally 1 per side (max 2)
Forward trunk flexion with flat palms Standing forward flexion with knees straight: palms must rest flat on the floor 1 (max 1)

The Beighton Score, despite its widespread use, has significant limitations. It does not assess the shoulder, hip, ankle, or temporomandibular joints — all of which are commonly hypermobile in EDS and commonly symptomatic. It does not capture the instability or laxity of spinal ligaments, sacroiliac joints, or the craniocervical junction. It does not account for the patient who was previously hypermobile but has developed secondary joint stiffness or arthritis. And it captures a static picture of mobility at one moment in time, not the dynamic instability and subluxation that defines the lived experience of hEDS. For these reasons, the 2017 criteria supplement the Beighton Score with the broader five-part questionnaire (5PQ) for historical hypermobility and additional clinical features that together provide a more complete diagnostic picture.

The 2017 hEDS Diagnostic Criteria — Three Criteria, All Required

Diagnosis of hypermobile EDS requires all three of the following criteria to be met:

2017 hEDS Diagnostic Criteria — Summary

Criterion 1: Generalised Joint Hypermobility. Beighton Score at or above the age- and sex-adjusted threshold, OR positive five-part questionnaire for historical hypermobility if current score is below threshold due to age-related stiffness or prior surgery. Criterion 2: Two or more of the following features — Feature A: systemic connective tissue manifestations (five or more of: unusually soft or velvety skin, mild skin hyperextensibility, unexplained striae at unusual sites, bilateral piezogenic papules, recurrent or multiple abdominal hernias, atrophic scarring, pelvic floor dysfunction, dental crowding, arachnodactyly, arm span:height ratio >1.05, mitral valve prolapse, aortic root dilatation). Feature B: positive family history — at least one first-degree relative meeting hEDS criteria independently. Feature C: musculoskeletal complications — one or more of recurrent joint dislocations or clinical joint instability, chronic pain in three or more joints for at least three months, chronic widespread pain for at least three months, atraumatic soft tissue injury. Criterion 3: All of the following prerequisites: absence of unusual skin fragility (which would suggest classical EDS), exclusion of alternative diagnosis (Marfan syndrome, Loeys-Dietz syndrome, other heritable connective tissue disorders), absence of causative COL5A1/5A2, COL1A1/1A2, or TNXB mutation (to exclude overlapping subtypes with genetic confirmation).

These criteria are specific, detailed, and publicly available. They are not obscure. They are published in the most widely read medical genetics journal in the world. The diagnostic failure in EDS is not a failure of criteria — it is a failure of dissemination. The general practitioner, the rheumatologist, and the orthopaedic surgeon who first see the EDS patient were not trained to apply these criteria. They were not trained to connect joint hypermobility with fatigue with dysautonomia with gastrointestinal dysmotility with chronic pain as expressions of a single disorder. They were trained to refer each symptom cluster to the relevant specialty, where each specialist treats their piece of the condition in isolation, and the underlying diagnosis is never assembled.

The EDS patient typically sees rheumatology for the joints, cardiology for the heart rhythm, gastroenterology for the dysmotility, urology for the bladder, neurology for the headaches, and psychiatry for the depression that results from having five progressive conditions and no unifying explanation. The geneticist who could explain all five is seen last — if at all.

The Body Under Siege

What EDS Does to a Human Life — The Full Clinical Spectrum

The symptom profile of EDS is one of the primary reasons it is misdiagnosed, dismissed, or attributed to psychological causes. Because defective connective tissue affects every organ system, EDS produces a clinical picture that cuts across every specialty in medicine. No single clinician encounters the full picture in a single consultation. And each clinician, encountering only their piece, tends to manage that piece in isolation — often successfully enough in the short term that the underlying cause continues to accumulate damage unchallenged.

The musculoskeletal picture — the visible foundation

Joint Hypermobility and Instability The defining physical feature: joints that move beyond their normal physiological range due to lax ligamentous support. In EDS, this is not merely a curiosity of flexibility — it is a structural liability. Hypermobile joints are inherently unstable. They sublux (partially dislocate without complete separation) and dislocate under loads that normal joints withstand without effort. The shoulder, hip, knee, ankle, wrist, and temporomandibular joint are commonly affected. Subluxations may occur spontaneously during sleep, in routine daily activity, or under minimal mechanical load. Each episode causes microtrauma to the joint capsule, ligaments, and surrounding soft tissue. Over years, this accumulating microtrauma produces early degenerative joint change, chronic synovitis, and fixed joint contracture that permanently reduces the mobility that was once excessive.
Chronic Musculoskeletal Pain Pain in EDS is multimechanistic and pervasive. Nociceptive pain arises from the recurring subluxations and the microtrauma they produce. Neuropathic pain arises from peripheral nerve entrapment in abnormally mobile soft tissue planes and from the small fibre neuropathy that is now recognised as a significant comorbidity in hEDS. Central sensitisation — the amplification of pain signals by a nervous system chronically overloaded with nociceptive input — develops over time and produces widespread pain that is disproportionate to any single identifiable structural source. This layered pain picture is what clinicians mischaracterise as fibromyalgia, chronic pain syndrome, or somatisation — and it is what patients are most frequently told is psychological in origin. The central sensitisation is real; it is also the predictable neurological consequence of years of undertreated peripheral pain. Treating the central sensitisation without addressing the structural source is like treating smoke without the fire.
Proprioceptive Deficit and Dyspraxia Proprioception — the body's sense of its own position in space — depends on mechanoreceptors embedded in ligaments, tendons, and joint capsules. When those structures are abnormally lax, the signals they send are distorted. EDS patients have documented deficits in proprioception that contribute directly to their injury rates: without accurate positional feedback, the protective neuromuscular reflexes that prevent joints from exceeding safe range are impaired, and subluxations occur in movements that should be physiologically safe. Dyspraxia — difficulty with motor planning and coordination — is reported by many EDS patients and may reflect both proprioceptive deficit and the neurological effects of chronic pain on motor cortex function. Targeted proprioceptive rehabilitation is a cornerstone of physiotherapy in EDS, but it requires a therapist who understands the condition — applying standard strengthening protocols to an EDS patient without proprioceptive training worsens instability.
Muscle Hypotonia and Fatigue Generalised muscle hypotonia is common in EDS, particularly in children, and may contribute to the early presentation of the condition as developmental delay or reduced athletic performance. In adults, muscle fatigue is disproportionate to exertion and does not resolve with rest in the way that normal exercise fatigue does. This is partly structural — muscles are working harder than usual to compensate for the ligamentous support they cannot rely on — and partly metabolic, reflecting the energetic cost of chronic pain processing, autonomic dysregulation, and the neuroinflammation associated with mast cell activation. Post-exertional malaise — a worsening of symptoms after physical or cognitive exertion that persists for hours to days — is reported by a significant proportion of hEDS patients and overlaps substantially with the diagnostic criteria for myalgic encephalomyelitis (ME/CFS), with which EDS frequently co-occurs.
Spinal Instability and Craniocervical Involvement The same ligamentous laxity that affects the peripheral joints also affects the spinal facet joints, the intervertebral disc annuli, and — critically — the ligaments of the craniocervical junction. Spinal instability in EDS produces chronic axial pain, radicular symptoms, and — at the craniocervical level — the brainstem compression of craniocervical instability (CCI) described in the first article of this series. Spondylolisthesis (vertebral slippage), sacroiliac joint instability, and coccydynia are common in EDS. Cervical instability produces headaches, visual disturbance, swallowing difficulty, and cognitive symptoms that are frequently attributed to migraine, anxiety, or functional neurological disorder before the structural basis is recognised.
Soft Tissue Injury and Poor Healing Tendons and ligaments in EDS are structurally abnormal: weaker, less elastic, and more prone to tears under loads that normal tissue withstands. Repetitive strain injuries, tendinopathies, and ligamentous tears occur at low mechanical thresholds. Wound healing is frequently delayed and may produce the atrophic, "cigarette-paper" scars characteristic of classical EDS. In hypermobile EDS, wound healing complications are less dramatic but still clinically significant: wounds dehisce under less tension than expected, sutures may pull through fragile tissue, and post-surgical healing is slower and more painful than clinicians who are not familiar with EDS anticipate. Every surgical team operating on an EDS patient should be aware of the connective tissue fragility and modify their wound closure technique accordingly.
The Autonomic Dimension

Beyond the Joints — The Systemic Cascade

The musculoskeletal picture is what gets EDS into the medical literature and into the awareness of rheumatologists and orthopaedic surgeons. The systemic cascade — the cardiovascular, neurological, gastrointestinal, immunological, and neuropsychiatric consequences of defective connective tissue throughout the body — is what makes EDS a life-altering condition and what medicine has been slowest to recognise as part of a unified disease.

Cardiovascular and autonomic dysfunction — the dysautonomia triad

Postural Tachycardia Syndrome (POTS) POTS — a sustained heart rate increase of 30 beats per minute or more (40bpm in adolescents) within ten minutes of standing, associated with symptoms of orthostatic intolerance but without sustained hypotension — affects an estimated 40–70% of hypermobile EDS patients in some cohort studies. The mechanism in EDS is multifactorial: venous pooling due to blood vessel laxity and impaired peripheral vasoconstriction; reduced intravascular volume related to poor venous tone; sympathetic nervous system overactivation compensating for inadequate peripheral resistance; and small fibre autonomic neuropathy. The result is a heart that races to compensate for orthostatic circulatory insufficiency that the vascular walls cannot prevent. POTS in EDS is not idiopathic — it has a structural explanation. And it is frequently not diagnosed because clinicians do not perform orthostatic vital signs, do not know to perform a tilt table test, and do not connect the tachycardia with the hypermobile joints in the same patient. Detailed coverage of POTS is available in Article 2 of this series.
Mitral Valve Prolapse (MVP) Mitral valve prolapse — the billowing of one or both mitral valve leaflets into the left atrium during systole — is more common in EDS than in the general population, reflecting the laxity of the valve leaflets and their chordal attachments. The mitral valve is a connective tissue structure; defective collagen produces the same ligamentous laxity there as in the peripheral joints. Most MVP in EDS is haemodynamically mild and does not require intervention. A minority of patients develop progressive mitral regurgitation that requires surgical correction. In classical EDS, MVP occurs more frequently and may be more severe. In all EDS patients, echocardiographic screening for valve pathology and aortic root dilatation is appropriate at diagnosis and periodically thereafter. In vascular EDS, aortic and arterial involvement is the dominant cardiovascular concern and requires a different surveillance protocol entirely.
Aortic Root Dilatation Mild aortic root dilatation is found at higher rates in EDS populations than in the general population, particularly in hEDS and classical EDS. The dilatation is usually mild and rarely progresses to the severe aortic dissection seen in Marfan syndrome — but it is not absent, and it requires monitoring. Annual echocardiography to track aortic root dimensions is reasonable practice for EDS patients. Any EDS patient with a first-degree relative with aortic pathology, or any patient whose aortic root measurement is approaching or exceeding the upper limit of normal for body surface area, should be under active cardiological surveillance. In vascular EDS, aortic and arterial surveillance is far more urgent — see the vEDS entry above.
Orthostatic Hypotension and Syncope While POTS is the more common autonomic presentation in EDS, frank orthostatic hypotension — a sustained drop in systolic blood pressure of 20mmHg or diastolic blood pressure of 10mmHg within three minutes of standing — also occurs, particularly in older patients. Neurocardiogenic (vasovagal) syncope — a reflex-mediated loss of consciousness triggered by prolonged standing, heat, pain, or emotional stress — is common and is often the presenting complaint that brings the patient to cardiology. Both presentations reflect the same underlying autonomic vulnerability: an inability to maintain adequate cerebral perfusion in the upright position. Non-pharmacological management (increased salt and fluid intake, compression garments, avoiding triggers) is first-line; pharmacological management with fludrocortisone, midodrine, or beta-blockers may be appropriate depending on the pattern of dysautonomia.

Gastrointestinal dysmotility — when the gut cannot hold its structure

The gastrointestinal tract is built from smooth muscle — but smooth muscle that depends on connective tissue for its architecture, its innervation, and its structural support. In EDS, GI dysmotility is extraordinarily common, frequently disabling, and almost universally either dismissed as functional or attributed to anxiety. The mechanisms are several: the smooth muscle of the gut may itself be affected by connective tissue abnormality; the enteric nervous system — the intrinsic neural network of the gut — may be compromised by the same small fibre neuropathy that affects peripheral autonomic nerves; and the structural support that normally holds the gut in its anatomical position may be insufficient, allowing visceral prolapse and abnormal mobility that impairs transit.

Gastroparesis and Delayed Gastric Emptying Delayed gastric emptying — documented on radionuclide gastric emptying scintigraphy — is common in hEDS. Symptoms include early satiety, postprandial fullness, nausea, vomiting, and bloating. Food that should empty from the stomach in four hours may remain for eight or more. The consequences include malnutrition (particularly if severe), medication malabsorption (drugs that should be absorbed from the stomach are not), and profound quality-of-life impact. Management includes dietary modification (small frequent meals, reduced fat and fibre), prokinetic agents (metoclopramide, domperidone, erythromycin at low doses), and in refractory cases gastric electrical stimulation. Nasojejunal feeding or jejunostomy may be necessary in patients with severe gastroparesis who cannot maintain adequate nutrition orally.
Small Intestinal Dysmotility Dysmotility may extend throughout the small bowel, producing either functional bloating and discomfort from bacterial overgrowth in sluggishly moving segments, or, conversely, episodic rapid transit with post-prandial urgency. Small intestinal bacterial overgrowth (SIBO), diagnosed on breath testing, is more prevalent in EDS patients than in the general population and contributes substantially to bloating, distension, flatulence, and altered stool form. Treatment with targeted antibiotics (rifaximin is most commonly used) and management of the underlying dysmotility is required; SIBO will recur if the underlying motility problem is not addressed.
Chronic Constipation and Pelvic Floor Dysfunction Slow-transit constipation — with reduced colonic peristalsis and prolonged stool transit times — is common. Pelvic floor dysfunction in EDS may involve either hypertonic (overactive, painful) or hypotonic (lax, prolapsing) pelvic floor musculature, and frequently involves structural pelvic organ prolapse: the same ligamentous laxity that dislocates peripheral joints allows the uterus, bladder, and rectum to descend from their anatomical positions. Pelvic organ prolapse in a young, otherwise healthy woman is a red flag for connective tissue disorder that gynaecologists and urogynaecologists should be trained to recognise. Rectocoele, cystocoele, and uterine prolapse requiring surgical repair in patients under forty should prompt EDS evaluation before surgery — because surgical repairs in EDS-defective tissue fail at rates substantially higher than in the general population, and the repair should be planned with that knowledge.
Hiatus Hernia and Gastro-oesophageal Reflux Hiatus hernia — migration of the stomach through the oesophageal hiatus in the diaphragm — is substantially more common in EDS than in the general population, reflecting the same structural laxity that allows pelvic organ prolapse. GORD (gastro-oesophageal reflux disease) is a near-universal complaint in EDS, often severe and refractory to standard proton pump inhibitor therapy. When GORD is refractory to treatment, a hiatus hernia should be sought radiologically. In EDS, surgical repair of hiatus hernia carries increased risk of recurrence due to the fragility of the diaphragmatic crura and the fascial planes used in reconstruction. Inguinal, umbilical, and incisional hernias are also significantly more common in EDS than in the general population.

Neurological and neuropsychiatric dimensions

Chronic Headache — Craniocervical and CSF-Related Chronic headache is reported by the majority of adult hEDS patients. The headache picture in EDS is heterogeneous and mechanistically important to distinguish. Craniocervical instability-related headache — typically suboccipital, worse with upright posture and neck movement, relieved by neck support or lying flat — reflects brainstem compression and abnormal cervical joint mechanics. Intracranial hypotension headache — bilateral, worse on standing, associated with tinnitus and nausea — may result from spontaneous CSF leaks through dural weaknesses at spinal nerve root sleeves, which are themselves connective tissue structures that may be structurally abnormal in EDS. Intracranial hypertension (elevated CSF pressure) is also reported and may produce a positional headache pattern distinct from hypotension. Each of these headache phenotypes has a specific diagnostic workup and specific treatment — none of them is tension headache, and none of them is anxiety.
Small Fibre Neuropathy (SFN) Small fibre neuropathy — a length-dependent degeneration of the thin unmyelinated C fibres and lightly myelinated A-delta fibres that carry pain, temperature, and autonomic signals — is documented in a significant proportion of hEDS patients on skin punch biopsy and quantitative sensory testing. The symptoms include burning, stinging, or electric-shock sensations in the feet and lower legs; allodynia (pain from normally non-painful stimuli such as touch or clothing); and autonomic manifestations including hyperhidrosis, anhidrosis, and abnormal pupillary responses. SFN in EDS may contribute directly to the chronic pain burden, may underlie the autonomic dysfunction, and may be responsible for some of the visceral hypersensitivity seen in EDS-related GI symptoms. Diagnosis requires either skin punch biopsy (quantifying intraepidermal nerve fibre density) or corneal confocal microscopy. Specific treatments for SFN are limited; sodium channel blockers (mexiletine) and some anticonvulsants may provide partial benefit.
Cognitive Dysfunction — "Brain Fog" Cognitive difficulties — impaired working memory, difficulty with concentration and word retrieval, slowed processing speed, reduced multitasking capacity — are reported consistently by EDS patients and are among the most functionally disabling symptoms outside of pain and fatigue. The mechanisms are poorly characterised but likely involve: cerebral hypoperfusion from dysautonomia (the orthostatic brain receives less blood); the neuroinflammatory effects of mast cell mediator release; the cognitive cost of processing chronic pain; the sleep disruption from pain and autonomic dysfunction; and possibly intrinsic neurological effects of the connective tissue disorder on the cerebrovascular architecture. Standard cognitive testing is often normal in EDS patients with significant subjective cognitive impairment, because the tests are not sufficiently sensitive to the pattern of deficits — which are real, measurable on more sensitive testing, and a legitimate disability.
Tethered Cord Syndrome and Craniocervical Instability EDS is the underlying connective tissue disorder in the craniospinal syndrome described across this series. The filum terminale — a connective tissue structure — loses its elastic compliance in hEDS and becomes fibrotic, tethering the spinal cord from below (Tethered Cord Syndrome, covered in Article 3). The ligaments of the craniocervical junction — also connective tissue — become excessively lax, producing brainstem compression from above (Craniocervical Instability, covered in Article 1). These are not coincidental comorbidities. They are direct anatomical consequences of defective collagen in specific connective tissue structures. Any EDS patient with neurological symptoms — bladder dysfunction, lower limb sensory changes, positional headache, brainstem symptoms — deserves evaluation of the full neuroaxis, from skull base to coccyx, at a centre with experience in craniospinal pathology.
The Mast Cell Layer

Mast Cell Activation Syndrome — The Third Member of the Triad

In the lexicon of EDS comorbidities, three conditions have come to be understood as a clinical triad: hEDS, POTS, and Mast Cell Activation Syndrome (MCAS). All three are more common together than any one of them is separately. All three are misdiagnosed routinely. And in patients with all three, the management of each is complicated by the presence of the other two in ways that generalist clinicians — managing each condition in isolation — systematically fail to account for.

Mast cells are connective tissue-resident immune cells. They are found in highest density at the interfaces between the body and the external environment — the skin, the gut mucosa, the respiratory epithelium, the bladder — and at perivascular locations throughout every organ. Their normal function is to serve as first responders to injury and pathogen exposure: they release pre-formed mediators (histamine, tryptase, heparin) and synthesise new mediators (prostaglandins, leukotrienes, cytokines) in response to IgE-mediated, non-IgE-mediated, and physical stimuli. In MCAS, mast cells activate inappropriately and excessively in response to triggers that do not represent genuine threats: foods, medications, temperature changes, physical pressure, emotional stress, and infections.

The link between EDS and MCAS is not yet fully understood at the molecular level, but several mechanisms have been proposed. Defective connective tissue may alter the microenvironment in which mast cells reside, changing the signalling cues they receive. Mast cell mediators, particularly tryptase, may in turn degrade connective tissue components, creating a bidirectional cycle in which EDS worsens MCAS and MCAS worsens EDS. Whatever the mechanism, the clinical implications are significant: EDS patients with MCAS react to a wider range of medications, tolerate anaesthesia and surgical procedures less predictably, experience more severe allergic and pseudoallergic reactions, and have a substantially higher symptom burden than EDS patients without MCAS. Detailed coverage of MCAS will follow in Article 6 of this series.

The Numbers

The Scale of What Is Not Being Found

~1 in 500
Estimated prevalence of hypermobile EDS — widely considered an undercount given systematic diagnostic failure
10–20 yr
Average diagnostic delay from first symptoms to EDS diagnosis in adults — representing years of preventable joint damage, autonomic deterioration, and systematic dismissal
>80%
Proportion of EDS patients reporting that at least one clinician attributed their symptoms primarily or entirely to anxiety, depression, or psychological causes before diagnosis

These numbers are not statistics. They are calendars — each year of diagnostic delay is a year of joint damage that appropriate physiotherapy could have slowed, a year of autonomic deterioration that volume loading and compression therapy could have stabilised, a year of mast cell activation that antihistamines and mast cell stabilisers could have dampened, a year of spinal cord tension that appropriate neurosurgical referral could have addressed. The neurological deficits, the articular damage, and the cardiovascular remodelling that accumulate during diagnostic delay are not retrievable. Early diagnosis does not cure EDS. It provides the window in which management prevents the consequences of undertreated disease.

Management

Treatment — A Multisystem Approach to a Multisystem Disease

EDS has no cure. No medication corrects the underlying collagen defect. The goal of management is to reduce symptom burden, prevent secondary joint damage, stabilise cardiovascular function, manage comorbidities, and preserve functional capacity over a lifetime. This requires a genuinely multidisciplinary team — not the nominal multidisciplinary team of sequential specialist referrals, but a coordinated, communicating team that understands EDS as a unifying diagnosis and treats its manifestations in the context of each other.

Physiotherapy — the cornerstone, and the most frequently delivered incorrectly

Physiotherapy is the single most important management intervention for musculoskeletal EDS, and it is the intervention most often delivered incorrectly by therapists not trained in hypermobility. The guiding principle is this: in EDS, joint stability depends on muscle strength because ligamentous stability is insufficient. Targeted strengthening of the muscles around hypermobile joints — particularly the rotator cuff for the shoulder, the quadriceps and hip abductors for the knee, the intrinsic foot muscles for the ankle, and the deep cervical flexors for the neck — provides the dynamic stabilisation that the passive ligamentous structures cannot. Exercises that improve proprioception — positional sense and reflex arc speed — are equally important. Low-resistance, high-repetition, closed-chain exercises (where the distal limb is in contact with a surface) are preferred over open-chain, high-resistance exercises that produce joint shear forces the lax capsule cannot absorb.

What is contraindicated in EDS physiotherapy — and what therapists without specific training routinely prescribe — is stretching. Stretching already-hypermobile joints does not improve their function. It further stresses already-compromised ligamentous and capsular tissue and accelerates the degenerative joint damage that EDS is already producing. The EDS patient who arrives at a physiotherapist with joint pain and is given a home stretching programme has received an intervention that is directly harmful. This is not a minority position. It is the consensus guidance of every specialist physiotherapy body that has published EDS-specific guidance.

Pharmacological management — targeting the comorbidities

There is no disease-modifying pharmacological therapy for EDS. Pain management, autonomic support, mast cell stabilisation, and management of specific comorbidities are the pharmacological targets.

Target / Comorbidity Pharmacological Approaches Key Considerations for EDS
Musculoskeletal pain (nociceptive) Paracetamol; low-dose NSAIDs with caution; tramadol (short-term); topical agents NSAIDs increase bleeding risk relevant to EDS tissue fragility. Opioids produce dependency without addressing the mechanical cause of pain. Avoid long-term opioid escalation; multidisciplinary pain management preferred.
Neuropathic / central sensitisation pain Low-dose tricyclics (amitriptyline, nortriptyline); SNRIs (duloxetine); low-dose naltrexone; pregabalin (with caution); gabapentin EDS patients frequently have paradoxical responses to medications. Start at the lowest dose and titrate slowly. Pregabalin may worsen fatigue and cognitive dysfunction. Low-dose naltrexone is emerging as a tolerated option in central sensitisation.
POTS / Dysautonomia Fludrocortisone; midodrine; beta-blockers (low-dose propranolol, ivabradine); increased salt and fluid intake; compression garments Volume expansion (salt/fluid) and compression are first-line. Pharmacological agents should be added to, not substituted for, non-pharmacological measures. Beta-blockers may worsen fatigue. Ivabradine (If-channel blocker) is often better tolerated in EDS-POTS than conventional beta-blockers.
MCAS H1 antihistamines (cetirizine, loratadine — low-sedation preferred); H2 antihistamines (famotidine); mast cell stabilisers (cromolyn sodium, ketotifen); quercetin; low-dose aspirin (for prostaglandin-dominant picture) EDS-MCAS patients frequently react to inactive excipients in tablets (dyes, fillers). Liquid formulations or compounded medications may be necessary. Trial of both H1 and H2 blockade before concluding antihistamines are ineffective. Cromolyn sodium has poor systemic absorption but may help GI MCAS symptoms.
Gastrointestinal dysmotility Prokinetics (metoclopramide, domperidone, low-dose erythromycin); antispasmodics for pain; rifaximin for SIBO; proton pump inhibitors for GORD; nutritional support Metoclopramide carries tardive dyskinesia risk with long-term use; domperidone preferred where available. Assess for SIBO before initiating prokinetics. Nutritional assessment essential in moderate-to-severe GI dysmotility; dietitian involvement is mandatory.
Vascular EDS (vEDS) Celiprolol (beta-1 selective with beta-2 agonist and alpha-2 antagonist properties); blood pressure optimisation; avoidance of arterial procedures where possible Celiprolol is the only agent with randomised trial evidence for reducing arterial events in vEDS. Invasive vascular procedures carry very high risk of arterial rupture; conservative management preferred wherever clinically feasible. Urgent surgical management of rupture by vascular surgeons with vEDS experience is essential when intervention is unavoidable.

Surgical considerations — operating on collagen-deficient tissue

Surgery in EDS patients demands specific pre-operative planning, intraoperative technique modification, and post-operative vigilance that most surgical teams are not trained to provide — because they do not know the patient has EDS, or because they know but do not fully appreciate its implications. Joint stabilisation surgery — particularly for the shoulder, hip, and knee — is performed in EDS patients when conservative management has failed and joint instability is functionally disabling or causing progressive articular damage. The outcomes of stabilisation surgery in EDS are substantially less predictable than in the general population: the same tissue fragility that produced the instability also affects the capsular tissue through which anchoring sutures are placed, the bone into which screws are inserted, and the healing response that consolidates the repair. Anchors pull through. Repairs stretch. Instability recurs. Surgeons who operate on EDS joints should be warned that standard surgical approaches and standard expectations of healing do not apply, and that post-operative rehabilitation protocols must be modified to account for prolonged healing and the risk of re-laxity.

"I had three shoulder surgeries before anyone mentioned Ehlers-Danlos. Each surgery repaired a labral tear and each tear recurred within eighteen months. After my diagnosis, my surgeon told me he wished he had known before the first operation. He would have managed my expectations differently, used different anchoring technique, and been less aggressive in the rehabilitation timeline. Twelve months of recovery for a repair that lasted eighteen. I was not told that was possible."

The psychological dimension — real and secondary, not primary

Anxiety and depression are common in EDS. The reasons are not mysterious. EDS is a progressive, painful, functionally disabling condition for which there is no cure. It produces disability in young people who expected different lives. It is systematically disbelieved by the medical profession — an experience of invalidation that compounds the disability with a specific and documented psychological harm. And the autonomic dysfunction of POTS produces symptoms — racing heart, shortness of breath, tremor, anxiety — that are physiologically generated and frequently misinterpreted as primary anxiety disorder both by clinicians and by the patients themselves.

The clinical imperative is to treat the psychological sequelae of EDS with genuine compassion and appropriate intervention — cognitive behavioural therapy, acceptance and commitment therapy, and pharmacological support where indicated — while absolutely refusing to allow psychological treatment to become a substitute for medical management of the structural disease. The patient with EDS who presents with anxiety is not presenting with primary anxiety disorder. They are presenting with anxiety in the context of a disabling, disbelieved, and undertreated structural condition. Treating the anxiety without treating the condition is a fundamental clinical error. Worse, offering psychological treatment as an alternative to further medical investigation — the clinical pathway of "we've ruled out everything serious, let's refer to psychology" — actively harms these patients by removing them from the investigative pathway at the moment when what they need is more investigation, not less.

The Children Who Are Not Found

EDS in Children — The Early Signs That Should Never Be Missed

EDS is present from birth. Collagen is present from conception. The diagnostic delay is not because EDS begins in adulthood — it is because the clinical presentation in childhood is systematically attributed to other causes, and the medical specialties that encounter children with EDS early are not trained to recognise it.

A child with hEDS typically presents with a cluster of features that are individually common and individually non-specific: late motor milestones (late walking, attributed to normal variation); recurrent ankle sprains, a term that normalises what is in fact joint instability; "growing pains" in the legs, a diagnosis that should be approached with clinical scepticism whenever pain is recurrent, nocturnal, or disproportionate to activity; easy bruising, attributed to normal childhood activity; recurrent abdominal pain, attributed to school anxiety or constipation; headaches, attributed to tension or screen use; and a general impression of being "clumsy" or "uncoordinated," which reflects the proprioceptive deficit of hypermobility. Each of these features, in isolation, is unremarkable. In combination, in a child with joint hypermobility, they are the paediatric signature of EDS — and their recognition requires a clinician who is looking for the pattern, not evaluating each symptom in isolation.

Paediatric red flags that should prompt EDS evaluation

Any child presenting with three or more of the following warrants assessment for EDS: generalised joint hypermobility (Beighton Score ≥4 or positive five-part questionnaire); recurrent joint sprains or subluxations across multiple joints without adequate traumatic explanation; delayed motor milestones without alternative neurological explanation; chronic or recurrent musculoskeletal pain in multiple sites; easy bruising beyond what is expected for the child's activity level; recurrent abdominal pain with no identified GI pathology; chronic headache, particularly positional; unexplained recurrent urinary tract infections or bladder dysfunction; skin that is unusually soft, velvety, or extensible; atrophic scarring at injury sites; and a first-degree relative with confirmed EDS or significant joint hypermobility with chronic pain. Paediatric rheumatology is the appropriate referral; clinical genetics referral may be needed if a genetic subtype is suspected.

The consequences of missed paediatric EDS are measured in the joint damage that accumulates during years of subluxations managed as isolated injuries; in the scoliosis that progresses without recognition of its connective tissue basis; in the school years lost to fatigue and pain that was attributed to school avoidance; and in the young adults who arrive at specialist EDS clinics in their twenties and thirties with established joint damage, chronic pain, fixed autonomic dysfunction, and a psychiatric history they accumulated while being told the problem was in their mind. These outcomes are not inevitable. They are the consequence of missed diagnosis. Earlier recognition changes them.

The Gender Dimension

EDS, Gender, and the Medicine of Dismissal

The epidemiology of EDS is striking and worth stating plainly. Hypermobile EDS is diagnosed in women at substantially higher rates than in men — estimated ratios range from 4:1 to 9:1 female to male in most clinical cohorts. Whether this reflects a true biological sex difference in EDS prevalence, a hormonal effect on collagen synthesis and laxity (oestrogen receptors are present on ligaments and may influence their mechanical properties, explaining clinical observations of symptom fluctuation with the menstrual cycle and with pregnancy), a difference in health-seeking behaviour, or a profound bias in clinical recognition — in which identical symptoms are taken more seriously in male than in female patients — is not fully resolved. The answer is likely all of the above.

What is resolved is the clinical experience. EDS patients — predominantly women — report, in survey after survey, the same litany of clinical encounters: the joint pain that was attributed to anxiety. The fatigue that was attributed to deconditioning or depression. The tachycardia that was attributed to panic attacks. The GI symptoms that were attributed to irritable bowel syndrome or eating disorder. The cognitive dysfunction that was attributed to low mood. The overall clinical picture that was attributed to medical attention-seeking or somatic symptom disorder. The EDS patient who finally receives a diagnosis most commonly reports that they found it themselves — through patient communities, through research, through recognition of their own symptoms in accounts written by others who had been through the same system — and then brought their hypothesis to a clinician willing to evaluate it. This is not how a medical system should work. It is how this medical system does work, for this patient population.

The average EDS patient does not fail to seek help. They seek help, are dismissed, seek help again, are psychiatrically labelled, seek help a third time, and eventually find the diagnosis themselves. The failure is not theirs. It is systematic, documented, and specific to conditions that predominantly affect women with complex multisystem presentations.

What Needs to Change

What Medicine Owes These Patients

The story of EDS in modern medicine is the story of this series in its most distilled form. A common, heritable, structurally explicable, clinically recognisable condition is being missed in the majority of patients who have it — for an average of a decade or more — while damage that could have been prevented continues to accumulate. The knowledge to diagnose EDS exists. The criteria are published. The specialists who can confirm the diagnosis are present in most major medical centres. The management strategies that reduce harm are documented and accessible. The failure is not in the availability of knowledge. It is in its distribution.

What needs to change is specific. Medical school curricula need to include EDS in their teaching on heritable connective tissue disorders — not as a rare genetic curiosity, but as a common condition with a characteristic clinical profile that every generalist is likely to encounter. Postgraduate training in rheumatology, paediatrics, neurology, cardiology, gastroenterology, and gynaecology needs to include EDS recognition as a core competency. Physiotherapy training needs to include hypermobility-specific rehabilitation principles that are genuinely different from standard musculoskeletal protocols. The diagnostic criteria need to be embedded in the clinical decision-support tools that generalists use — so that a patient presenting with joint hypermobility plus chronic pain plus fatigue plus POTS triggers a prompt toward EDS evaluation rather than a referral to psychology.

The genetic research infrastructure around hEDS needs to be adequately funded. The absence of a confirmatory genetic test for the most prevalent EDS subtype is not intellectually acceptable in 2026 — and it has direct clinical consequences, because the patients most in need of diagnostic validation are the ones whose diagnosis remains entirely dependent on clinical recognition by an adequately trained clinician. The EDS Society and the international consortium of clinical researchers working on the hEDS genetics problem deserve research investment commensurate with the prevalence of the condition they are studying.

What EDS patients consistently report they need

Based on patient community surveys and advocacy submissions: a clinician who recognises joint hypermobility as a systemic finding, not an isolated curiosity; connection of the joint symptoms to the autonomic symptoms to the GI symptoms to the neurological symptoms as expressions of one underlying disorder; access to a physiotherapist with specific hypermobility training who will not prescribe stretching; referral to a geneticist or EDS-specialist clinical genetics service where the diagnosis can be confirmed and the subtype determined; honest and specific counselling about what is known and what is not — including the absence of a genetic test for hEDS and the implications of that; appropriate cardiovascular screening (echocardiogram, orthostatic vital signs) without being told these investigations are unnecessary; recognition of MCAS as a legitimate comorbidity and trial of antihistamine therapy; and the end of psychiatric re-labelling of progressive multisystem symptoms in patients whose connective tissue, not their psychology, is the source of the problem.

The Call

If You Recognise Yourself in This

If you are reading this and recognising your own body in it — the joints that have always been "too flexible," that have sprained and subluxed since childhood in ways that seemed disproportionate; the fatigue that no amount of sleep resolves; the heart that races when you stand; the stomach that does not empty, that bloats and nauseates regardless of what you eat; the burning in your feet; the headaches that are always there, worse when you are upright; the skin that bruises too easily and heals too slowly; the years of being told it is anxiety, it is deconditioning, it is a low pain threshold, it is all in your head — this section is for you.

The symptoms you have are not a coincidence. They are not five separate conditions that you are unlucky enough to have simultaneously. They have a single structural explanation in the connective tissue that is supposed to hold the body together and is, in your body, not doing so with the reliability that health requires. That explanation has a name. The name is Ehlers-Danlos Syndrome. It is real, it is common, it is heritable, and it is diagnosable by criteria that are publicly available and clinically established.

The path to diagnosis requires finding a clinician who applies those criteria. The EDS Society maintains a directory of clinicians with EDS experience. Patient communities — the EDS Society forums, the hypermobility patient networks, the condition-specific support groups — hold the accumulated knowledge of thousands of people who have navigated this system and can direct you toward the clinicians who know what they are looking for. Bring documentation of your full symptom picture — joints, fatigue, autonomic symptoms, GI symptoms, neurological symptoms, skin findings — to your consultations. If you have a family history, document it. If you have photographs of your joint range, bring them. If you have had prior diagnoses of fibromyalgia, POTS, MCAS, chronic fatigue, or functional symptoms, bring those records. The pattern is the diagnosis. The pattern is specific. And it is the pattern of Ehlers-Danlos Syndrome.


The healthcare system's failure in EDS is not, at its core, a failure of technology or resources. The criteria for diagnosis are free, published, and specific. The clinical examination findings — the Beighton Score, the skin extensibility, the atrophic scars, the visible hypermobility — require no investigation beyond trained hands and informed eyes. The systemic comorbidities — POTS, MCAS, tethered cord, craniocervical instability — each have their own diagnostic pathways once the clinician knows to look for them. The failure is upstream of all of that: it is in the mind of the clinician taking the history, who was not taught to connect the symptoms of a multisystem connective tissue disorder, and in the training of the medical system that produced them. Correcting that failure requires education, prioritisation, and the political will to treat a condition that predominantly affects women as a legitimate object of clinical and research attention. That is not an extraordinary demand. It is the minimum that medicine owes the people it has failed for decades.

Collagen is the most abundant protein in the human body. It is everywhere. When it is wrong, everything built on it is compromised. This is not a rare disease of rare people. This is a common disease of common people, hiding in the most ordinary of places — in the joints that bend too far, in the skin that stretches too much, in the heart that races when its owner simply stands up — waiting for someone who knows what they are looking at.

This is the fourth in a series of articles on the conditions that fall through the widest cracks in modern medicine. Next: Complex Nerve Compression — the structural nerve entrapments that produce chronic pain and neurological deficits that are dismissed as functional, and that require specific surgical and interventional approaches that most patients never reach.