Hypermobility Spectrum Disorder vs. Hypermobile Ehlers-Danlos Syndrome: Understanding Differences and Management

What is HSD vs hEDS?

Hypermobility Spectrum Disorder (HSD) and hypermobile Ehlers-Danlos Syndrome (hEDS) are both conditions characterized by joint hypermobility, but they differ significantly in their diagnostic criteria, systemic involvement, and genetic implications. While HSD encompasses symptomatic joint hypermobility that doesn't meet the full criteria for hEDS, hEDS is a more severe, multi-systemic hereditary connective tissue disorder.

Understanding Joint Hypermobility

Joint hypermobility refers to the ability of a joint to move beyond its normal range of motion. While often benign and sometimes advantageous (e.g., in dancers or gymnasts), for some individuals, it can lead to chronic pain, instability, and a range of associated symptoms. Historically, terms like "Joint Hypermobility Syndrome (JHS)" were used, but with advancements in understanding, the International Ehlers-Danlos Society (IEDS) introduced updated classifications in 2017, leading to the current distinctions between HSD and hEDS.

What is Hypermobility Spectrum Disorder (HSD)?

Hypermobility Spectrum Disorder (HSD) is a diagnosis given to individuals with symptomatic joint hypermobility who do not fully meet the diagnostic criteria for hypermobile Ehlers-Danlos Syndrome (hEDS). It acknowledges that hypermobility exists on a spectrum of severity and impact.

Key Characteristics of HSD:

• Symptomatic Hypermobility: Individuals experience symptoms related to their hypermobility, such as chronic pain (arthralgia, myalgia), fatigue, joint instability (subluxations/dislocations), and often proprioceptive deficits.
• Variable Presentation: The severity and range of symptoms can vary widely among individuals, from localized joint pain to widespread systemic issues.
• Diagnosis of Exclusion: HSD is often considered a diagnosis of exclusion. It is applied when a person has symptomatic hypermobility but their presentation does not entirely fulfill the stringent criteria required for hEDS.
• No Specific Genetic Marker: Unlike some other Ehlers-Danlos Syndrome types, there is currently no specific genetic marker identified for HSD.
• Impact on Function: Despite not meeting hEDS criteria, HSD can significantly impact an individual's quality of life, daily activities, and exercise capacity.

What is hypermobile Ehlers-Danlos Syndrome (hEDS)?

Hypermobile Ehlers-Danlos Syndrome (hEDS) is the most common type of Ehlers-Danlos Syndrome, a group of hereditary disorders affecting connective tissues, primarily the skin, joints, and blood vessel walls. It is a systemic disorder, meaning it can affect multiple body systems beyond just the musculoskeletal system.

Key Characteristics of hEDS:

• Systemic Connective Tissue Disorder: hEDS is characterized by generalized joint hypermobility alongside a constellation of other systemic manifestations indicative of a more widespread connective tissue defect.
• Diagnostic Criteria (2017 IEDS Criteria): Diagnosis of hEDS requires meeting all three of the following criteria:
  • Criterion 1: Generalized Joint Hypermobility (GJH): Assessed using the Beighton Score (a 9-point scale).
  • Criterion 2: Systemic Manifestations and/or Family History: This includes at least two of the following features:
    • Skin involvement (soft, velvety skin; mild skin hyperextensibility; atrophic scarring).
    • Chronic musculoskeletal pain (lasting >3 months).
    • Positive family history of hEDS.
    • Recurrent joint dislocations/subluxations.
    • Pelvic floor, rectal, or uterine prolapse.
    • Dental crowding and high, narrow palate.
    • Hernias (umbilical, inguinal, diaphragmatic).
    • Foot deformities (e.g., pes planus).
  • Criterion 3: Exclusion of Other Diagnoses: This is crucial. Other connective tissue disorders (e.g., Marfan syndrome, other EDS types, autoimmune conditions) must be ruled out.
• Genetic Basis (Presumed): While the specific gene mutation for hEDS has not yet been identified, it is understood to be a genetic disorder with an autosomal dominant inheritance pattern. This means a person has a 50% chance of passing it on to each child.
• Multi-Systemic Impact: Individuals with hEDS often experience a broader range of symptoms, including dysautonomia (POTS), gastrointestinal issues, mast cell activation syndrome (MCAS), chronic fatigue, and dental problems, in addition to musculoskeletal issues.

Key Differences and Relationship Between HSD and hEDS

The primary distinction between HSD and hEDS lies in the extent of systemic involvement and the rigor of diagnostic criteria.

• Spectrum vs. Syndrome: HSD represents a "spectrum" of symptomatic hypermobility, while hEDS is a defined "syndrome" with specific, multi-systemic diagnostic criteria that must be met.
• Severity of Connective Tissue Involvement: While both involve dysfunctional connective tissue, hEDS implies a more widespread and severe defect affecting multiple organ systems beyond just the joints.
• Diagnostic Precision: The 2017 hEDS criteria are designed to be quite specific, ensuring that only individuals with a clear multi-systemic presentation receive the hEDS diagnosis. HSD serves as a category for those who are symptomatic but don't quite fit the hEDS mold.
• Fluidity of Diagnosis: It's important to note that a diagnosis can sometimes evolve. An individual initially diagnosed with HSD might later meet the full criteria for hEDS as their symptoms progress or become clearer, or as diagnostic understanding improves. Conversely, the management strategies often overlap significantly.

Clinical Presentation and Management

Both HSD and hEDS can lead to a variety of symptoms, many of which overlap.

Common Symptoms:

• Musculoskeletal Pain: Chronic widespread pain, joint pain, muscle pain.
• Joint Instability: Frequent subluxations (partial dislocations) or full dislocations.
• Fatigue: Often debilitating and disproportionate to activity level.
• Proprioceptive Deficits: Poor body awareness, leading to clumsiness or falls.
• Dysautonomia: Conditions like Postural Orthostatic Tachycardia Syndrome (POTS), causing dizziness, lightheadedness, and fainting upon standing.
• Gastrointestinal Issues: Bloating, constipation, reflux, delayed gastric emptying.
• Skin Manifestations: Soft, velvety skin, easy bruising (more common in hEDS).
• Anxiety and Depression: Often comorbid due to chronic pain and illness burden.

Management Strategy: Management of both HSD and hEDS is typically multi-faceted and focuses on symptom management, functional improvement, and prevention of complications.

• Physical Therapy: Crucial for strengthening muscles around unstable joints, improving proprioception, balance, and posture. Emphasis is on stability and controlled movement, not flexibility.
• Pain Management: Pharmacological (NSAIDs, neuropathic pain medications) and non-pharmacological approaches (heat/cold therapy, TENS, massage, acupuncture).
• Occupational Therapy: To adapt daily activities and conserve energy.
• Orthotics and Bracing: To provide support and stability to hypermobile joints.
• Psychological Support: To address chronic pain, fatigue, and associated mental health challenges.
• Lifestyle Modifications: Pacing activities, ensuring adequate rest, proper nutrition, and hydration.
• Medication: For specific systemic symptoms (e.g., managing dysautonomia, GI issues).

The Role of Exercise and Movement

For individuals with HSD and hEDS, exercise is not just beneficial; it's a cornerstone of management. However, it must be carefully tailored to avoid exacerbating symptoms or causing injury.

Principles of Exercise for Hypermobility:

• Focus on Stability, Not Flexibility: Unlike general fitness recommendations, individuals with hypermobility should avoid extreme stretching or movements that push joints to their end range of motion. The goal is to build strength and stability around the joints.
• Proprioceptive Training: Exercises that enhance body awareness and joint position sense are vital. Examples include balance exercises (e.g., standing on one leg, wobble board), single-leg squats, and controlled movements.
• Low-Impact Strengthening: Prioritize exercises that build muscle strength without high impact on joints. Examples include swimming, cycling (stationary), elliptical, Pilates, and resistance training with light weights and high repetitions.
• Core Stability: A strong core provides a stable base for limb movements, reducing stress on peripheral joints. Planks, bird-dog, and specific Pilates exercises are excellent.
• Gradual Progression: Start slowly and gradually increase intensity and duration. Listen to your body and avoid "pushing through" pain.
• Avoid Hyperextension: Be mindful of joint locking or hyperextension, especially in knees and elbows. Maintain a slight bend.
• Professional Guidance: Working with a physical therapist or an exercise physiologist experienced in hypermobility is highly recommended. They can design a safe and effective exercise program, teach proper form, and help identify compensatory movement patterns.

Living with Hypermobility: Practical Considerations

Managing life with HSD or hEDS often requires a holistic approach that extends beyond medical treatment and exercise.

• Pacing and Energy Conservation: Understanding and respecting energy limits is crucial to prevent post-exertional malaise. Break tasks into smaller chunks, take frequent breaks, and prioritize activities.
• Pain Management Strategies: Develop a diverse toolkit for managing chronic pain, including physical therapies, mindfulness, heat/cold, and appropriate medication.
• Advocacy and Education: Educating oneself and others (family, friends, employers) about the condition can foster understanding and support.
• Assistive Devices: Consider the use of ergonomic tools, supportive footwear, or braces as needed to reduce strain and improve function.
• Nutritional Support: While no specific diet cures these conditions, a balanced, anti-inflammatory diet can support overall health and potentially alleviate some GI symptoms.

Seeking a Diagnosis and Professional Guidance

If you suspect you have symptomatic joint hypermobility, seeking a diagnosis from a healthcare professional is the first step. This typically involves:

• Consulting a Physician: Start with your primary care physician, who may refer you to specialists such as a rheumatologist, geneticist, or a rehabilitation medicine physician.
• Comprehensive Evaluation: A thorough medical history, physical examination (including a Beighton score assessment), and potentially genetic testing (to rule out other EDS types or related conditions) will be conducted.
• Multidisciplinary Team: Management often benefits from a team approach involving physicians, physical therapists, occupational therapists, pain specialists, and mental health professionals.

Understanding the distinctions between HSD and hEDS is vital for accurate diagnosis, appropriate management, and optimizing the quality of life for individuals living with these complex conditions. While the diagnostic labels differ, the core principles of managing symptomatic hypermobility—focusing on stability, strength, and a holistic approach—remain paramount.