HSD vs. hEDS: Understanding the Difference and Getting the Right Diagnosis

Hypermobility Spectrum Disorder (HSD) and hypermobile Ehlers-Danlos Syndrome (hEDS) are two closely related conditions that exist on a continuum of heritable connective tissue disorders. Both involve joint hypermobility, musculoskeletal symptoms, and autonomic dysfunction, but they are diagnosed differently and carry different implications for management and prognosis. Understanding the distinction — and why it is often blurry — is essential for patients navigating this diagnostic landscape.

The Diagnostic Criteria

hEDS is diagnosed using the 2017 International Classification of EDS criteria, which requires ALL of the following:

1. Generalized joint hypermobility (GJH): Beighton score ≥5/9 (or ≥4/9 for adults over 50)
2. Two or more of the following features:
   • Feature A: Systemic manifestations of connective tissue disorder (5 of 12 minor criteria)
   • Feature B: Positive family history (first-degree relative with hEDS)
   • Feature C: Musculoskeletal complications (3 or more of: chronic widespread pain, recurrent joint dislocations, chronic fatigue, anxiety, marfanoid habitus, skin involvement)
3. Absence of other connective tissue disorders (Marfan syndrome, classical EDS, vascular EDS, etc.)
4. Absence of unusual skin fragility (which would suggest classical EDS)

HSD is a diagnosis of exclusion — it is given to patients with symptomatic joint hypermobility who do not meet the full criteria for hEDS. HSD is further classified as:

• Generalized HSD (G-HSD): Generalized hypermobility without meeting hEDS criteria
• Peripheral HSD (P-HSD): Hypermobility limited to hands and feet
• Localized HSD (L-HSD): Hypermobility at a single joint or region
• Historical HSD (H-HSD): Past hypermobility no longer demonstrable (common in older patients)

Why the Distinction Is Often Difficult

The 2017 hEDS criteria were designed to be strict, ensuring that hEDS represents a more severe phenotype. However, in practice, the distinction between HSD and hEDS is often clinically meaningless — patients with G-HSD and hEDS have similar symptoms, similar rates of dysautonomia and MCAS, and respond to similar treatments.

The criteria have also been criticized for:

• Requiring a Beighton score that may be normal in older patients (joints stiffen with age)
• Requiring a family history that may not be known or recognized
• Lacking a genetic test (unlike other EDS subtypes, hEDS has no identified causative gene)
• Being difficult to apply consistently across different clinicians

As a result, many patients who are clinically identical receive different diagnoses depending on which clinician they see and how strictly the criteria are applied.

Autonomic Dysfunction in HSD and hEDS

Both HSD and hEDS are associated with high rates of dysautonomia:

The mechanism linking connective tissue hypermobility to dysautonomia is not fully understood but likely involves:

• Lax blood vessel walls that allow excessive venous pooling
• Impaired proprioception leading to poor postural reflexes
• Connective tissue abnormalities affecting autonomic nerve sheaths
• MCAS as a shared underlying mechanism

Getting the Right Diagnosis

Who to see: A geneticist, rheumatologist, or connective tissue specialist with experience in EDS/HSD. General practitioners and many specialists are unfamiliar with the 2017 criteria.

What to bring: A list of all joints that have been hypermobile (even if they are no longer), family history of hypermobility or connective tissue problems, and documentation of any dislocations, subluxations, or connective tissue complications.

The Beighton score: The Beighton score tests 9 specific maneuvers (see our dedicated Beighton Score article). A score of 5/9 or higher in adults under 50 meets the GJH criterion for hEDS. However, the Beighton score should be interpreted in the context of age, sex, and ethnicity — women and younger patients typically score higher.

Why the label matters (and when it doesn't): The hEDS label may be important for insurance coverage, disability applications, and accessing specialized care. However, for day-to-day management, HSD and hEDS are treated similarly — physical therapy, joint protection, pain management, and treating comorbid POTS and MCAS.

ChatDys resources: Track your joint symptoms, dislocations, and autonomic symptoms in the Health Tracker. Upload your genetic data to Genetics to check for variants in connective tissue genes (COL5A1, TNXB, FLNB). Review our Beighton Score Guide for detailed instructions on self-assessment.