Hypermobile Ehlers-Danlos syndrome (hEDS) is a connective tissue disorder characterized by joints that move beyond the normal range, chronic pain, and a wide constellation of symptoms affecting the skin, gut, heart, and nervous system. It is the most common form of Ehlers-Danlos syndrome, accounting for 80 to 90 percent of all EDS cases. The traditional estimate puts EDS prevalence at about 1 in 5,000 people, though growing evidence suggests hEDS is significantly underdiagnosed.
How hEDS Affects the Body
Connective tissue is the structural scaffolding of the body. It holds joints together, gives skin its strength, and supports blood vessels, organs, and the digestive tract. In hEDS, that scaffolding is faulty, which creates problems that ripple across multiple systems.
The hallmark feature is generalized joint hypermobility, meaning joints bend further than they should. This leads to frequent subluxations (partial dislocations) and full dislocations that can happen spontaneously or from minimal force, like reaching for a shelf or rolling over in bed. Soft tissue injuries are common and often acutely painful. Over time, the repeated micro-damage to joints and surrounding tissue drives chronic pain that many people describe as constant background noise punctuated by flares.
Beyond the joints, hEDS causes soft, stretchy skin that bruises easily and heals with thin, widened scars. Abdominal hernias and pelvic organ prolapse can develop because the connective tissue supporting internal organs is weaker than normal. Dental crowding is another common feature. Some people have mild mitral valve prolapse or slight widening of the aortic root, though these heart findings rarely cause serious complications on their own.
Chronic Pain and Central Sensitization
Pain in hEDS is not just about unstable joints. While acute injuries from subluxations and dislocations are a major source of suffering, many people develop chronic pain that persists even without a clear injury. This pain is often neuropathic, meaning it originates from the nervous system itself rather than from damaged tissue. People describe burning, tingling, or shooting sensations alongside the deep aching in muscles and joints.
Researchers believe the constant barrage of pain signals from unstable joints can eventually rewire the nervous system’s pain processing. This phenomenon, called central sensitization, means the brain and spinal cord become hypersensitive, amplifying normal signals into painful ones. Nerve entrapment, where peripheral nerves get compressed by shifting tissues, adds another layer. The result is a pain experience that often looks disproportionate to any visible injury, which historically led many patients to be dismissed by doctors.
The Overlap With POTS, Gut Problems, and Fatigue
One of the most frustrating aspects of hEDS is the cluster of conditions that frequently travel with it. Up to 40 percent of people with EDS develop some form of orthostatic intolerance, and a significant subset meet the criteria for postural orthostatic tachycardia syndrome (POTS). POTS causes a rapid heart rate, lightheadedness, palpitations, chest pain, and fatigue when standing. The leading theory is that lax connective tissue in blood vessel walls allows veins to stretch too much, causing blood to pool in the legs. The heart then races to compensate for reduced blood flow to the brain.
Gastrointestinal dysfunction is similarly widespread. Functional bowel disorders, slow stomach emptying (gastroparesis), acid reflux, and bloating are all common. The autonomic nervous system, which controls involuntary functions like digestion and heart rate, appears broadly disrupted in hEDS. Reduced sweat production, sleep disorders including sleep apnea, migraines, and bladder dysfunction all point to this systemic autonomic problem.
Chronic fatigue is nearly universal. It is distinct from normal tiredness and often resembles the bone-deep exhaustion seen in chronic fatigue syndrome. Mast cell activation, where immune cells release inflammatory chemicals inappropriately, has been identified in a subset of patients and may contribute to flushing, hives, and widespread inflammation. Anxiety disorders are also common, though whether this is a direct neurological effect of hEDS or a consequence of living with unpredictable symptoms remains debated.
Why hEDS Is So Hard to Diagnose Genetically
There are 13 recognized subtypes of Ehlers-Danlos syndrome, and all of them except hEDS have identified genetic causes that can be confirmed with a lab test. hEDS stands alone as the only major subtype diagnosed purely through clinical criteria. No single gene has been definitively linked to it.
This isn’t for lack of trying. The condition likely involves multiple genes rather than one, and the symptoms vary so widely between patients that different people may carry different genetic variants leading to similar outcomes. A 2025 genome-wide study identified seven genes with statistically significant associations, all encoding proteins involved in structural integrity and the cellular skeleton. One gene related to skin barrier function was altered in roughly 70 percent of hEDS subjects compared to only 10 percent of controls. Variants in collagen-related genes appeared in 63 percent of hEDS patients versus 17 percent of controls, and immune system gene variants showed up in 74 percent versus 30 percent.
These findings suggest hEDS may involve a combination of structural protein defects, immune system differences, and even mitochondrial (cellular energy) dysfunction. But the research is still building toward a usable genetic test, and for now, diagnosis depends entirely on a clinician’s evaluation.
How hEDS Is Diagnosed
Diagnosis follows the 2017 international criteria and has three main requirements. First, generalized joint hypermobility is assessed using the Beighton score, a nine-point scale that tests specific movements: bending forward to place your palms flat on the floor with straight knees, hyperextending each elbow and knee past straight, bending each pinky finger back beyond 90 degrees, and touching each thumb to the forearm. A score of four or more (adjusted for age, since flexibility naturally decreases) is considered positive.
Second, you need to meet at least two of three additional feature categories. These include specific skin and tissue findings (stretchy skin, easy bruising, unexplained stretch marks, hernias, pelvic prolapse), a family history of hEDS in a first-degree relative, and musculoskeletal complications like chronic widespread pain or recurrent dislocations.
Third, other connective tissue disorders must be ruled out, including other EDS subtypes that can be confirmed genetically. The process often requires several visits and a detailed history, which is part of why the average patient waits years before receiving a correct diagnosis.
hEDS vs. Hypermobility Spectrum Disorder
Not everyone with symptomatic joint hypermobility qualifies for an hEDS diagnosis. People who have flexible joints along with chronic pain, frequent injuries, or poor body awareness but don’t meet the full 2017 criteria are diagnosed with a hypermobility spectrum disorder (HSD). This isn’t a lesser condition. HSD can be just as painful and disabling as hEDS, and the management approach is essentially the same. The distinction exists mainly for research purposes, to create more uniform study populations.
There are several HSD subtypes. Generalized HSD involves widespread hypermobility similar to hEDS. Peripheral HSD affects mainly the hands and feet. Localized HSD involves a single joint or body region. Historical HSD applies when hypermobility was clearly present earlier in life but has since decreased with age. In clinical practice, distinguishing between these subtypes and hEDS requires careful evaluation, and many specialists recommend that patients who narrowly miss the hEDS criteria be re-evaluated over time as symptoms evolve.
Managing hEDS Day to Day
There is no cure for hEDS, and no medication targets the underlying connective tissue defect. Management focuses on stabilizing joints, reducing pain, and building the muscular support system that compensates for loose ligaments.
Physical therapy is the cornerstone. But the approach differs from standard rehab. Effective programs for hEDS emphasize neuromuscular control, which means training muscles to activate properly and stabilize joints during movement rather than simply building raw strength. Exercises typically progress from isometric holds (contracting a muscle without moving the joint) to controlled movement through a range of motion, from non-weight-bearing positions to weight-bearing ones, and from both-sides-at-once to single-limb work. Balance and proprioception training, which improves your brain’s awareness of where your body is in space, is critical because this sense is often impaired in hEDS.
The progression matters. Starting too aggressively can trigger subluxations and flares. A physical therapist familiar with hypermobility will begin with mid-range isometrics using light resistance and advance slowly. Deep neck flexor activation, resisted ankle exercises against a wall or band, and wrist stability work with resistance bands are typical starting points. Over time, the goal is building enough muscular endurance and joint awareness to participate in broader exercise like swimming, cycling, or Pilates.
Surgical Considerations
People with hEDS face elevated risks during any surgical procedure. Tissue fragility means stitches may not hold as well, wound healing is often slower, and bruising or hematoma formation is more likely. Joint laxity complicates patient positioning during surgery, because limbs can inadvertently hyperextend under anesthesia. Any physical manipulation carries a higher risk of tissue trauma.
This doesn’t mean surgery is off the table, but it does mean your surgical and anesthesia team needs to know about your diagnosis ahead of time. Planning for longer recovery periods, using gentler tissue-handling techniques, and monitoring for complications are all standard adjustments when operating on someone with a connective tissue disorder.