Building Your Understanding of Hypermobility Syndrome (hEDS and HSD)

For many people living with hypermobility, the path to a name for their symptoms is often long and exhausting. You may have spent years being told your pain is “growing pains,” that you are simply “double-jointed,” or that your symptoms are all in your head ^[1][2]. In 2017, the medical community updated the way these conditions are classified to provide more clarity, yet many patients still find themselves caught between different labels like hEDS and HSD ^[3].

Understanding these conditions starts with recognizing that your symptoms are real, even if they don’t always fit into a single box. Whether you meet the strict criteria for a specific syndrome or fall elsewhere on the spectrum, the impact on your life and the need for support remain the same.

The 2017 Framework: hEDS vs. HSD

In 2017, international experts established new, stricter criteria to distinguish between different types of hypermobility ^[2]. It is helpful to think of these as points on a single spectrum of connective tissue health rather than entirely separate diseases.

Hypermobile Ehlers-Danlos Syndrome (hEDS)

To be diagnosed with hEDS, you must meet three specific “criteria” simultaneously ^[3]:

1. Generalized Joint Hypermobility (GJH): This is measured using the Beighton Score, a 9-point system checking the flexibility of your pinky fingers, thumbs, elbows, knees, and spine ^[4]. The cutoff for “generalized” hypermobility changes with age; for example, children usually need a 6/9, while adults may only need a 5/9 or 4/9 ^[4][5].
2. Systemic Features and Family History: You must show signs that your connective tissue is affected elsewhere, such as unusually soft or mildly stretchy skin, unexplained stretch marks, certain types of hernias, or a first-degree relative who also meets these criteria ^[2][6].
3. Exclusion of Other Conditions: Your doctor must rule out other types of EDS (which often have known genetic markers) and other autoimmune or inflammatory conditions that can cause joint pain ^[7][8].

Hypermobility Spectrum Disorders (HSD)

If you have symptomatic joint hypermobility—meaning your joints are flexible and it is causing you pain or instability—but you do not meet all the strict systemic “check-boxes” for hEDS, you may be diagnosed with HSD ^[2].

It is a common misconception that HSD is a “milder” version of hEDS. Research shows that people with HSD can experience the same levels of chronic pain, fatigue, and disability as those with hEDS ^[9]. The difference is primarily in which diagnostic boxes are checked, not in the severity of the person’s daily struggle.

The Biology of Hypermobility

Unlike other types of Ehlers-Danlos syndrome, there is currently no single “universal gene” that identifies everyone with hEDS or HSD ^[10]. Instead, the condition is considered multifactorial, meaning it likely results from a combination of different genetic variations and environmental factors ^[11].

While it is hypothesized that the core issue may lie in the extracellular matrix (ECM)—the complex “scaffolding” that holds your cells together—this remains a research observation rather than a confirmed diagnostic model ^[12]. Some studies of skin cells from patients suggest that proteins meant to keep tissues strong—like collagen, fibronectin, and tenascin—may be disorganized ^[13][14]. It is important to remember that hEDS and HSD do not generally produce the marked organ fragility associated with rarer EDS subtypes, like Vascular EDS ^[4].

Beyond the Joints: A Multisystem Condition

Because connective tissue is found throughout your entire body, clinical overlaps can appear in many different systems ^[8]. Keep in mind these are associations, and alternative causes should always be considered:

• Pain and Nerve Sensitivities: Some patients experience central sensitization, where the nervous system becomes “wound up” and over-responsive to pain signals ^[15]. Some studies also report emerging evidence of small-fiber neuropathy (damage to the tiny nerve endings in the skin), which may coexist and cause burning pain or tingling, though it requires proper evaluation ^[16][17].
• The Autonomic Nervous System: It is common for some patients to experience dysautonomia, where the system that controls “automatic” functions like heart rate and blood pressure doesn’t work perfectly ^[18]. This may present as POTS (Postural Orthostatic Tachycardia Syndrome), causing dizziness, fainting, or a racing heart when you stand up ^[17].
• Proprioception: Many people with hEDS/HSD have impaired proprioception—your body’s “internal GPS” that tells you where your limbs are in space ^[15]. This can make you feel clumsy or lead to more frequent joint injuries.

Why Diagnosis Can Be Difficult

Getting a clear diagnosis is often a challenge for several reasons:

• Historical Terminology: Older terms like “Joint Hypermobility Syndrome” or “EDS-Hypermobility Type” were used for decades. Many doctors are still catching up to the 2017 updates ^[19][1].
• Stricter Criteria: Since the 2017 criteria are much tougher, some people who were previously told they had hEDS may now technically fall into the HSD category ^[1].
• The “Invisible” Nature: Because many of the systemic signs aren’t visible on a standard X-ray or blood test, symptoms are often dismissed until a specialist looks at the whole picture ^[8][2].

If you are navigating this journey, remember that your symptoms deserve management and validation regardless of which specific acronym—hEDS or HSD—is currently in your medical record. The goal of treatment remains focused on stabilizing joints, managing pain, and improving your quality of life.