Ehlers-Danlos syndrome (EDS) is a group of inherited conditions that affect connective tissue, the protein-rich material that holds your skin, joints, blood vessels, and organs together. The core problem is faulty collagen, the most abundant protein in your body. When collagen doesn’t form or function correctly, tissues throughout the body become too stretchy, too fragile, or both. The combined prevalence of all types is at least 1 in 5,000 people worldwide, though milder forms likely go undiagnosed far more often.
How Collagen Defects Cause EDS
Collagen acts like the scaffolding inside your connective tissue. It gives skin its strength, joints their stability, and blood vessel walls their structure. In most types of EDS, inherited gene mutations disrupt how collagen is built or processed. The specific gene affected determines which type of collagen is faulty, and that determines which tissues are most vulnerable.
In classical EDS, the mutations hit type V collagen, which helps organize collagen fibers in skin and tendons. In vascular EDS, the defect involves type III collagen, which reinforces blood vessels and organ walls. At least six of the recognized EDS subtypes have an identified collagen defect. These mutations are passed from parent to child, most commonly in an autosomal dominant pattern, meaning a single copy of the altered gene from one parent is enough to cause the condition.
The 13 Types and Why Hypermobile EDS Stands Apart
There are 13 recognized subtypes of EDS, but two account for the vast majority of cases. Hypermobile EDS (hEDS) is the most common, estimated to affect 1 in 5,000 to 20,000 people. Classical EDS is the second most common, occurring in roughly 1 in 20,000 to 40,000 people. The remaining subtypes are rare, some extremely so.
What makes hEDS unusual is that researchers still haven’t pinpointed a single gene responsible for it. Every other EDS subtype has a defined genetic cause that can be confirmed with a blood test. hEDS does not. Recent genome-wide studies suggest it’s polygenic, meaning many common genetic variants each contribute a small amount of risk rather than one gene causing the whole condition. This is why hEDS diagnosis remains clinical, based on a physical exam and symptom history, and why it often takes years of evaluation across multiple specialists before someone gets a definitive answer.
Recognizing the Symptoms
The hallmark features of EDS are joint hypermobility, unusually stretchy skin, and tissue fragility. But because connective tissue is everywhere in the body, symptoms can show up in places that seem unrelated to joints.
Joint hypermobility means your joints bend further than normal. This isn’t just being “flexible.” It leads to frequent joint dislocations or subluxations (partial dislocations), chronic joint pain, and early-onset arthritis. Many people with EDS describe their joints as feeling unstable, like they could slip out of place during everyday activities.
Skin involvement varies by type. In classical EDS, the skin is velvety soft, stretches well beyond normal, and bruises easily. Wounds heal slowly and often leave wide, papery scars. In hEDS, skin changes tend to be subtler, sometimes just unusually soft skin that bruises without obvious cause. People with EDS may also find their skin is hypersensitive to adhesives like medical tape or athletic tape.
Symptoms Beyond the Joints
EDS is far more than a joint condition. Research tracking systemic complications found that the average EDS patient had nearly three nonmusculoskeletal conditions alongside their joint problems. The most common include autonomic dysfunction, gastrointestinal issues, headaches, and cardiac abnormalities.
Autonomic dysfunction (dysautonomia) disrupts the involuntary nervous system that controls heart rate, blood pressure, and digestion. It often shows up as dizziness when standing, heart palpitations, and fainting episodes. A specific form called POTS (postural orthostatic tachycardia syndrome), where heart rate spikes abnormally upon standing, is particularly common in people with hEDS.
Gastrointestinal problems affect roughly half of EDS patients. The most frequently reported issues are chronic abdominal pain (69% of those with GI symptoms), frequent nausea and vomiting (54%), acid reflux (40%), and chronic constipation or diarrhea (29%). These likely stem from the same connective tissue weakness affecting the gut wall and the nerves that control digestion.
About 30% of EDS patients in one study had at least one cardiac condition, most commonly heart rhythm irregularities (23%), widening of the aortic root (15%), or heart valve abnormalities (9%).
The POTS and Mast Cell Connection
Three conditions cluster together often enough that clinicians now watch for all of them: hEDS, POTS, and mast cell activation syndrome (MCAS). In one study, 66% of patients who had both POTS and EDS also reported symptoms consistent with a mast cell disorder. Mast cells are immune cells that release histamine and other inflammatory chemicals. When they activate inappropriately, the result is flushing, itching, low blood pressure, asthma-like symptoms, diarrhea, bloating, and cramping.
The connection may be partly mechanical. Mast cell activity can loosen blood vessel walls, causing blood to pool in the legs. This pooling triggers the rapid heart rate of POTS when you stand up. Recognizing this triad matters because treating one component, such as managing mast cell overactivation, can improve the others.
Vascular EDS: The High-Risk Subtype
Vascular EDS (vEDS) is rare but serious. It results from mutations in the gene for type III collagen, making arteries and organ walls dangerously fragile. People with vEDS face a risk of arterial dissections, where inner layers of an artery tear and separate, potentially leading to aneurysms or ruptures. Collapsed lungs and ruptured internal organs causing severe bleeding are also possible.
The timeline is sobering: most people with vEDS experience at least one severe complication by age 20. By age 40, the risk of a life-threatening event reaches 80%. This subtype requires ongoing monitoring and careful avoidance of activities or procedures that could stress fragile blood vessels.
How EDS Is Diagnosed
For most subtypes, genetic testing can confirm a diagnosis by identifying the specific collagen gene mutation. For hEDS, the process is different. Doctors use clinical criteria established in 2017, which assess joint hypermobility, systemic features, and family history.
Joint hypermobility is measured with the Beighton score, a nine-point scale. You earn one point for each of these movements you can perform: bending forward to place your palms flat on the floor with straight knees, hyperextending each elbow past straight (two points), hyperextending each knee past straight (two points), bending each thumb to touch the forearm (two points), and bending each pinky finger backward past 90 degrees (two points). A score of 5 or higher in adults generally indicates generalized hypermobility, though the threshold varies by age and sex.
The 2017 criteria have been criticized for being overly strict and for not capturing the full range of systemic symptoms that hEDS causes. Revisions have been discussed but no official update has been released as of 2025.
Managing EDS Day to Day
There is no cure for EDS, and treatment focuses on protecting joints, managing pain, and preventing complications. Physical therapy is the cornerstone. The goal is building muscle strength to compensate for loose ligaments and improving proprioception, your body’s sense of where your joints are in space.
Strengthening programs have shown measurable results. A 16-week heavy shoulder strengthening program performed three times per week produced a 51% improvement in shoulder stability and significant reductions in fatigue. Isometric exercises, where you contract a muscle without moving the joint, are particularly effective because they build strength with minimal joint stress. Research shows meaningful strength gains in shoulder muscles with isometric training, and similar principles apply to stabilizing knees, hips, and the spine.
The most effective rehabilitation programs combine multiple approaches: strength training, postural stabilization exercises, cognitive behavioral strategies for pain management, energy conservation techniques, joint protection education, and nutritional support. Learning to pace activities and protect vulnerable joints during daily tasks is just as important as formal exercise.
Bracing or taping can help stabilize problem joints, though skin sensitivity to adhesives is common in EDS and may limit taping options. Surgical repair of repeatedly dislocating joints is sometimes considered, but outcomes can be unpredictable because the underlying tissue weakness means surgical repairs may not hold as well as they would in someone without EDS.