Ehlers-Danlos Syndromes (EDS)

What the Ehlers-Danlos syndromes are

The Ehlers-Danlos syndromes (EDS) are a group of thirteen inherited connective tissue disorders. Connective tissue is the body’s scaffolding — the collagen and related proteins that give skin, ligaments, tendons, blood vessels, and organs their strength and stretch. In EDS, that scaffolding is built or maintained differently, which can lead to joint hypermobility, skin differences, and tissue that is more fragile or stretchy than usual, to varying degrees depending on the type.

An important fact frames everything else: twelve of the thirteen types have an identified gene and can be confirmed with a genetic test. The most common type by far — hypermobile EDS (hEDS) — is the exception. It has no known gene yet, so it is diagnosed entirely by a strict set of clinical criteria. The symptoms are real and reflect a genuine physical difference in how the body is built; the point of careful diagnosis is to get people the right help and the right monitoring.

How hypermobile EDS is actually diagnosed — the 2017 criteria

This is the part that is most often misunderstood. A diagnosis of hEDS is not “being flexible,” and it is not “being told you have it.” It means a clinician has confirmed that all three of the 2017 International Classification criteria are met at the same time. There is no blood test that makes the diagnosis — it is clinical.

Criterion 1 — Generalized joint hypermobility, measured with the Beighton score (a nine-point check of specific joints). Because flexibility declines with age, the passing score is age-adjusted: 6 or more in children and adolescents, 5 or more in adults up to 50, and 4 or more over 50. (The Beighton score only checks a few joints and can miss people whose shoulders, hips, or jaw are the problem; a short five-point history questionnaire helps when someone was very flexible as a child but has since stiffened.)

Criterion 2 — At least two of these three features must be present: (A) at least five of twelve systemic signs of a connective tissue disorder, such as unusually soft or velvety skin, mild skin stretchiness, unexplained stretch marks, small bumps on the heels (piezogenic papules), a high narrow palate or dental crowding, long slender fingers, or certain heart findings; (B) a first-degree relative who independently meets the criteria; and (C) musculoskeletal complications such as chronic widespread pain or recurrent joint dislocations and instability.

Criterion 3 — Other conditions are ruled out. This is the step most often skipped, and it matters most. Because hEDS has no gene test, genetic testing is used to exclude the EDS types that do have one — especially vascular EDS, the rare dangerous type that affects blood vessels and must not be missed — as well as classical EDS, Marfan syndrome, and Loeys-Dietz syndrome, which need different monitoring. Skin fragility and certain other findings point away from hEDS toward these other diagnoses.

A related point: hEDS and hypermobility spectrum disorder (HSD) sit on one shared spectrum. If the full hEDS criteria are not met but symptomatic hypermobility is present, HSD is the appropriate label — and, importantly, the management is essentially the same. The label matters less than the plan. (The criteria are currently being revised through an international effort, with an update expected in 2026.)

Orthopaedic manifestations

The bone-and-joint side of EDS is usually what brings people to an orthopaedic surgeon. Common manifestations include:

• Joint hypermobility and a sense of joints being “loose” or unstable
• Recurrent partial or full dislocations — often the kneecap, shoulder, or fingers — sometimes with little or no trauma
• Chronic widespread joint and muscle pain, and easy fatigue with activity
• Flat feet, and sometimes scoliosis or other alignment differences
• Soft-tissue strains and sprains, and a tendency to bruise easily

The cornerstone of orthopaedic care is not surgery — it is graded strengthening and physical therapy to stabilize and protect the joints, along with activity pacing and bracing where useful. Surgery is used selectively, because results in hypermobile tissue can be less predictable; it is reserved for clear structural problems rather than for hypermobility itself.

Common misconceptions

• “Being very flexible means I have EDS.” — Hypermobility is common, and most flexible people are healthy. It is necessary but not sufficient: hEDS requires the full criteria, including systemic features and the exclusion of other conditions.
• “There is a blood test that diagnoses hEDS.” — There is not. hEDS is the one EDS type without a gene test; genetic testing is used to rule other conditions out, not to confirm hEDS.
• “If I have EDS I should avoid exercise, and any pain means damage.” — The opposite is closer to the truth: appropriate, graded strengthening is the single most effective treatment, and inactivity tends to make instability and pain worse.
• “EDS explains every symptom I have.” — hEDS travels with certain conditions (for example, some people also have dysautonomia or digestive issues), but not everything is EDS. A careful evaluation still matters so other treatable problems are not missed.

None of this is meant to dismiss real symptoms. The aim is the opposite: an accurate diagnosis is what unlocks the right treatment, the right specialists, and the right monitoring — and what prevents a dangerous look-alike like vascular EDS from being overlooked.

How we help and what to expect

A precise diagnosis changes the plan: vascular EDS calls for vascular surveillance, Marfan and Loeys-Dietz call for heart and aortic monitoring, and hEDS or HSD calls for a rehabilitation-first approach. For hypermobility-related pain and instability, care centers on physical therapy and strengthening, pacing, bracing, pain management, and — only when clearly needed — selected procedures, often with several specialties working together.

It helps to bring any prior genetic testing, your family history, a list of which joints dislocate or give way, and your questions, so the visit can focus on a clear, useful plan.

Learn more

The Ehlers-Danlos Society — 2017 International Classification & diagnostic criteria: ehlers-danlos.com

The Ehlers-Danlos Society — hEDS/HSD criteria review (“Road to 2026”): ehlers-danlos.com

This information is for educational purposes only and does not replace evaluation by a qualified clinician. A formal diagnosis of these conditions means that established, published criteria have been met — not simply that someone has been told they have the condition — and the workup often involves genetics, cardiology, or infectious-disease and rheumatology specialists alongside orthopaedic care.