HSD vs. hEDS: Understanding Hypermobility Spectrum Disorder vs. Hypermobile EDS

For patients navigating the world of joint hypermobility, the distinction between Hypermobility Spectrum Disorder (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS) can be a source of confusion and frustration. While both conditions share the hallmark of hypermobile (or “double-jointed”) joints, the 2017 international classification created a brighter line between them. Understanding this distinction is crucial for receiving an accurate diagnosis, accessing appropriate care, and advocating for your health.

This article will explore the key differences between HSD and hEDS, the diagnostic criteria for each, and why this distinction—while sometimes controversial—matters for patients.

What is the Difference Between HSD and hEDS?

Prior to 2017, many people with significant joint hypermobility and related symptoms were diagnosed with what was then called Ehlers-Danlos Syndrome, Hypermobility Type (or EDS-HT). However, the diagnostic criteria were broad, leading to a very diverse group of patients under one umbrella.

In 2017, an international consortium of experts revised the diagnostic criteria for all types of Ehlers-Danlos syndromes. They made the criteria for hypermobile EDS (hEDS) much more specific and stringent. Simultaneously, they introduced a new diagnosis: Hypermobility Spectrum Disorder (HSD). Essentially, HSD became the diagnosis for patients with symptomatic joint hypermobility who did not fully meet the strict criteria for hEDS or another connective tissue disorder.

Think of it as a spectrum. On one end, you have people with asymptomatic joint hypermobility—they are simply more flexible than average. As symptoms like pain, instability, and other systemic issues arise, they move along the spectrum into HSD. At the far end of the spectrum is hEDS, which has the most extensive and specific set of diagnostic criteria.

The 2017 Diagnostic Criteria for hEDS

To be diagnosed with hEDS today, a person must meet all three of the following criteria. This is a critical point: meeting only one or two is not enough for an hEDS diagnosis.

Criterion 1: Generalized Joint Hypermobility (GJH)

This is assessed using the Beighton score, a nine-point scale that measures hypermobility in specific joints. The threshold for GJH varies by age:

• ≥6 for pre-pubertal children and adolescents
• ≥5 for pubertal men and women up to age 50
• ≥4 for men and women over age 50

Even if a patient’s Beighton score is one point below the cutoff, they can still meet this criterion if they can answer “yes” to two or more of the following historical questions:

• Can you now (or could you ever) place your hands flat on the floor without bending your knees?
• Can you now (or could you ever) bend your thumb to touch your forearm?
• As a child, did you amuse your friends by contorting your body into strange shapes or could you do the splits?
• As a child or teenager, did your shoulder or knee cap dislocate on more than one occasion?
• Do you consider yourself “double-jointed”?

Criterion 2: Systemic Features of a Connective Tissue Disorder

This criterion requires the presence of two or more of the following three features (A, B, and C). Feature A requires at least five systemic manifestations.

Feature A (at least five must be present):

• Unusually soft or velvety skin
• Mild skin hyperextensibility
• Unexplained striae (stretch marks) at the back, groin, thighs, breasts, or abdomen in an adolescent or pre-pubertal woman without a history of significant weight changes.
• Bilateral piezogenic papules of the heel (small, fatty hernias on the sides of the heels)
• Recurrent or multiple abdominal hernias
• Atrophic scarring (scars that are thin and depressed)
• Pelvic floor, rectal, and/or uterine prolapse
• Dental crowding and high or narrow palate
• Arachnodactyly (abnormally long and slender fingers)
• Arm span-to-height ratio ≥1.05
• Mitral valve prolapse (MVP)
• Aortic root dilation with a Z-score >+2

Feature B:

• A positive family history, with one or more first-degree relatives independently meeting the diagnostic criteria for hEDS.

Feature C (must have at least one):

• Musculoskeletal pain in two or more limbs, recurring daily for at least 3 months.
• Chronic, widespread pain for ≥3 months.
• Recurrent joint dislocations or frank joint instability, in the absence of trauma.

Criterion 3: Exclusion of Other Conditions

Finally, all of the following prerequisites must be met:

1. There is no unusual skin fragility, which would prompt consideration of other types of EDS.
2. All other heritable and acquired connective tissue disorders are excluded. This includes other types of EDS, Marfan syndrome, Loeys-Dietz syndrome, and autoimmune conditions like Lupus or Rheumatoid Arthritis.
3. Any other diagnoses that may include joint hypermobility are excluded.

What is Hypermobility Spectrum Disorder (HSD)?

If a patient has symptoms related to joint hypermobility but does not meet all three criteria for hEDS, they will likely be diagnosed with HSD. The diagnosis of HSD acknowledges that the patient's symptoms are real and deserving of treatment, even if they don't fit into the narrow box of hEDS.

HSD can be further categorized based on which joints are affected (e.g., Generalized HSD, Peripheral HSD, Localized HSD), but the key takeaway is that it is a diagnosis for symptomatic hypermobility that is not explained by another condition.

Why Does the Distinction Matter?

The creation of these two distinct categories has been a subject of debate among patients and clinicians. Some feel the hEDS criteria are too strict and exclude people who are genuinely suffering. Others believe the specificity is necessary for research and to differentiate hEDS from other conditions.

Here’s why the distinction can be important:

• Insurance and Disability: A diagnosis of hEDS, as a named genetic disorder, can sometimes carry more weight with insurance companies and disability applications than the less-specific HSD diagnosis. This is not always the case, but it is a reality for some patients.
• Research: By creating a more homogeneous group of patients under the hEDS label, researchers can better study the underlying genetic causes and disease mechanisms. This is crucial for developing targeted treatments in the future.
• Validation: For some patients, receiving a specific diagnosis like hEDS can be validating after years of being told their symptoms are “all in their head.”

Treatment is Largely the Same

It is vital to understand that regardless of whether you are diagnosed with HSD or hEDS, the management and treatment approach is generally the same. Treatment focuses on managing symptoms and improving quality of life. This typically includes:

• Physical Therapy: To strengthen muscles around the joints, improve proprioception (your sense of body position), and prevent injury.
• Pain Management: A multi-faceted approach that may include medication, physical therapy, and other modalities.
• Management of Comorbidities: Both HSD and hEDS are associated with a range of other conditions, such as Postural Orthostatic Tachycardia Syndrome (POTS), Mast Cell Activation Syndrome (MCAS), and gastrointestinal issues. Treating these comorbidities is a key part of managing the overall condition.

If you have symptomatic hypermobility, it is essential to work with a doctor who is knowledgeable about these conditions. They can perform a thorough evaluation, provide an accurate diagnosis, and develop a comprehensive treatment plan tailored to your specific needs.

The Bottom Line

The distinction between HSD and hEDS is a relatively new development in the medical understanding of joint hypermobility. While the 2017 criteria established a clear diagnostic pathway for hEDS, HSD provides a diagnosis for those who are equally symptomatic but do not meet the strict criteria. The most important thing for patients to know is that both are real, recognized medical conditions. The treatment for both focuses on symptom management and is largely identical. Patient advocacy is key—continue to seek out knowledgeable healthcare providers and fight for the care you deserve, regardless of the label you are given.

Related Articles

• Types of EDS: Hypermobile, Classical, Vascular, and All 13 Subtypes
• MCAS and EDS: Why Mast Cell Disease and Connective Tissue Disorders Co-Occur
• Physical Therapy for EDS: Exercises, Stabilization, and What to Avoid
• Hypermobility Spectrum Disorder: Diagnosis, Symptoms, and Management