Hypermobility Spectrum Disorder (HSD) and Its Relationship to Hypermobile Ehlers-Danlos Syndrome (hEDS)
Hypermobility Spectrum Disorder (HSD) is a clinical diagnosis given to individuals with symptomatic joint hypermobility who do not meet the strict diagnostic criteria for hypermobile Ehlers-Danlos syndrome (hEDS). Although the two conditions are currently categorized separately, growing research and expert opinion suggest that they are best understood as points on a shared clinical spectrum.
Historical Context and Diagnostic Changes
Historically, individuals with generalized joint hypermobility and related symptoms were often diagnosed with either “joint hypermobility syndrome” (JHS) or “Ehlers-Danlos syndrome, hypermobility type” (EDS-HT). These terms were frequently used interchangeably, as both described patients with chronic pain, joint instability, soft tissue fragility, and fatigue—yet lacked a specific molecular marker.
The 1997 Villefranche criteria grouped these conditions under the hypermobile type of EDS, but diagnostic ambiguity persisted. In 2017, an international consortium revised the classification system. They introduced new, more stringent criteria for diagnosing hEDS and created the category of HSD to describe individuals who have symptomatic hypermobility but do not meet all the required criteria for hEDS.
One motivation for these changes was to improve diagnostic precision in research settings. Narrowing the criteria for hEDS was intended to facilitate gene discovery by identifying a more homogenous group of patients. However, this reclassification also had unintended consequences for clinical care and patient experience.
Diagnostic Criteria and Clinical Presentation
Under the 2017 framework:
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hEDS requires generalized joint hypermobility, a combination of musculoskeletal and systemic features, and the exclusion of other diagnoses.
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HSD is diagnosed when an individual has symptomatic joint hypermobility but does not meet all the criteria for hEDS.
For children and adolescents, the diagnostic process is more complex. Many clinical features of hEDS do not appear until later adolescence or adulthood. As a result, younger individuals are often diagnosed with HSD initially, with the understanding that the diagnosis may evolve over time.
In practice, the symptoms of HSD and hEDS are nearly indistinguishable. Both groups frequently experience
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Widespread musculoskeletal pain
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Joint instability, subluxations, or dislocations
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Fatigue
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Gastrointestinal issues
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Orthostatic intolerance and other forms of autonomic dysfunction
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Headaches and sleep disturbances
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Psychological symptoms, including anxiety and depression
Studies show that both conditions result in similarly reduced quality of life, high rates of disability, and comparable burdens of pain and fatigue. Subtle differences may exist (such as higher rates of skin findings or dysautonomia in hEDS), but these rarely affect clinical management or functional outcomes.
Challenges with Healthcare Recognition
Despite the clinical similarities, individuals diagnosed with HSD often face greater difficulty obtaining appropriate care and recognition. Multiple studies and qualitative reports have shown that:
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Healthcare providers may view HSD as a “less serious” or vague diagnosis compared to hEDS.
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Patients with HSD report lower satisfaction with healthcare, often citing disbelief, dismissal, or lack of knowledge among providers.
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Feelings of invalidation are common, with some patients fearing that their diagnosis will not be recognized as legitimate or that they will be denied needed care, accommodations, or insurance coverage.
These challenges have significant emotional and practical consequences. Patients with HSD frequently describe experiences of medical gaslighting, difficulty accessing specialists, and frustration with a fragmented system of care. These barriers contribute to psychological distress, including anxiety, depression, and feelings of isolation.
The stigma associated with the HSD label is compounded by its newer, less familiar terminology. In contrast, the term "Ehlers-Danlos syndrome" often carries more weight in clinical settings, even though the symptom burden may be the same. As a result, patients with HSD may encounter increased skepticism from providers unfamiliar with the current classification system.
Management: Unified and Individualized
Despite the diagnostic distinction, management approaches for HSD and hEDS are virtually identical. Both conditions are treated using the same evidence-based, multidisciplinary, and individualized strategies.
Key components of care include
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Physical and occupational therapy to improve joint stability, proprioception, and daily function. Therapy programs tailored specifically for EDS/HSD are often more effective than standard regimens.
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Pain management, beginning with non-pharmacologic strategies such as pacing, exercise, and CBT, with cautious use of medications like NSAIDs or acetaminophen.
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Mental health support, addressing the psychological burden of chronic symptoms and difficult care experiences.
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Multispecialty involvement, often including cardiologists, gastroenterologists, neurologists, and psychologists.
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Assistive devices and activity modifications, as needed, to reduce joint strain and support mobility.
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Patient education on joint protection, injury prevention, and self-management.
Studies have shown no meaningful differences in response to treatment between individuals with HSD and those with hEDS. However, the patient experience may differ substantially due to the way the diagnosis is perceived by the medical system.
Long-Term Outcomes and Psychosocial Impact
Both HSD and hEDS are chronic, often disabling conditions with lifelong impacts on quality of life. Common challenges include
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Persistent and widespread pain
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Fatigue and poor stamina
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Mobility limitations and injury risk
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Poor sleep and autonomic symptoms
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Psychological distress
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Difficulty accessing coordinated care
Children and adolescents with HSD face similar functional impairments as those with hEDS. Fatigue, pain, multisystem complaints, and impaired postural control are key drivers of reduced quality of life. These symptoms can affect school participation, friendships, physical activity, and self-esteem.
Negative experiences with healthcare—including delayed diagnosis, disbelief, and lack of validation—are particularly harmful. These interactions can erode trust in the medical system, reduce treatment adherence, and worsen mental health.
A Shared Spectrum and Future Directions
Emerging scientific evidence increasingly supports a spectrum model that views HSD and hEDS as phenotypic variations of the same underlying disorder. This view is bolstered by
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A shared biomarker found in the blood of individuals with both HSD and hEDS, believed to reflect abnormal breakdown of the extracellular matrix.
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Overlapping gene expression profiles related to connective tissue structure and integrity.
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Promising advances in imaging tools (e.g., elastography) that reveal subtle differences in tissue mechanics not visible in standard evaluations.
These findings have fueled calls to revise diagnostic criteria again—this time to reunify HSD and hEDS under a single, flexible framework that recognizes the full range of symptom presentations. The goal is to ensure that all affected individuals are taken seriously and receive appropriate care, regardless of whether they meet the current threshold for hEDS.
Summary
Hypermobility Spectrum Disorder (HSD) and hypermobile Ehlers-Danlos Syndrome (hEDS) are closely related conditions that share nearly all clinical features, treatment strategies, and long-term outcomes. Although the current classification system distinguishes them based on specific diagnostic criteria, emerging research and patient experience suggest they belong to a shared clinical spectrum.
The distinction between HSD and hEDS can carry significant consequences—not because of differences in symptoms or needs, but because HSD is often taken less seriously by healthcare providers. This can make it harder for patients with HSD to access appropriate care and support, contributing to emotional distress and reduced quality of life.
Recognizing HSD as a legitimate and serious connective tissue disorder is essential. All individuals with symptomatic hypermobility—whether diagnosed with HSD or hEDS—deserve comprehensive, patient-centered, and respectful care. As the medical community continues to refine its understanding of these conditions, future diagnostic frameworks may move toward unifying these labels to reflect the shared reality of those affected.