What is Ehlers-Danlos Syndrome?
Photo by Kishan Kanojia on Unsplash
(Quick-ish Read: 6 to 8 minutes)
(Last updated: March 2026)
Preface (Please Read First)
I really struggled to write this article for you.
There are so many confounding elements in this topic that writing anything short of a textbook chapter on EDS feels wildly incomplete. The description and diagnosis of EDS are full of exceptions, variations, and unsolved mysteries.
This profound lack of clarity is a major part of the reason why diagnosing and treating EDS and HSD is so challenging.
Here’s how I’ve handled this conflict. I’ve treated this as an introductory article, not a comprehensive guide. It’s a short-ish piece of content that can help you get a broad view of what EDS is, so you can determine whether or not you want to dive deeper.
If you reach the end, and think that some or all of this description applies to you, then I’ll include links to some of the best resources I know of.
If I’m honest, Generalized Hypermobility, Hypermobility Spectrum Disorder, and hEDS are my areas of expertise as a chiropractor. The more rare forms of EDS, and the complexities that they carry with them, are not. And I want you (and anyone else who is trying to figure out where they fall on this spectrum) to have access to the experts and their work in this field.
Now, let’s get started.
What is Ehlers-Danlos Syndrome?
Ehlers-Danlos Syndrome (EDS) is a family of rare inherited connective tissue disorders characterized by these 3 main attributes:
Joint hypermobility: joints that are flexible beyond the typical range
Skin hyperextensibility: unusually stretchy skin, which is often notably soft and has a doughy texture
Tissue friability: soft tissues (skin, muscle, tendon, fascia) that are more easily injured and slower to recover than is typical. Normally seen as easy bruising, skin irritation, thin scar formation, and/or easy muscle injury with slow recovery.
These signs present to different degrees in the different subtypes, but they are the core characteristics upon which the diagnosis was created.
EDS is the most common disorder associated with Generalized Hypermobility (though significantly less than 1% of people with Generalized Hypermobility can be properly diagnosed with EDS). As such, it often becomes important for people who have symptoms associated with hypermobility to properly classify their experience between Hypermobility Spectrum Disorder (HSD) and Ehlers-Danlos Syndrome.
(More on this topic in a future post.)
The Subtypes
EDS is currently made up of 13 distinct subtypes. 12 of the 13 subtypes describe unique variations in connective tissue, each associated with 1 or more specific genes per subtype.
These 12 identified subtypes together make up about 10% of all EDS diagnoses.
The final subtype (Hypermobile Ehlers-Danlos Syndrome (hEDS)) has yet to have genetic markers identified, so it is diagnosed based on clinical presentation and family history.
hEDS currently accounts for roughly 90% of EDS diagnoses.
(Note: A reassessment is taking place in 2026. The new diagnostic guide for the Ehlers-Danlos Syndromes and Hypermobility Spectrum Disorder is expected to be published on December 1, 2026.)
The Experience of EDS
Life with EDS is complex. Because connective tissue is the foundational substance of the whole human body, symptoms of a connective tissue disorder are often widespread, varied, and confounding.
When various symptoms are looked at individually, they tend to defy diagnosis - looking a bit like a bunch of things, but not exactly like one known diagnosis. It is only in looking at all of the symptoms as a whole that things start to make sense. This is why diagnosis of EDS (especially hEDS) can take an average of 10 years to get right.
Beyond the core characteristics, some of the most common signs and symptoms are:
Chronic or recurring muscle and/or joint pains
Headaches (sometimes migraines)
Slow recovery from exercise or exertion
Chronic fatigue
Stretch marks without significant change in body composition (most often around the hips, groin, and/or shoulders)
Sleep disturbances
High sensory sensitivity
Skin sensitivity
Sensitivity to heat and/or cold
People with EDS are also more likely (though are not guaranteed) to experience one or more of the following co-existing conditions:
Digestive Challenges
Auto-immune conditions
Dysautonomia - especially Postural Orthostatic Tachycardia Syndrome (POTS)
Neurodivergence - including ADHD, Autism, and/or Dyslexia
Mast Cell Activation Syndrome (MCAS)
Please note: This is not a perfect or comprehensive list. There is some disagreement about the association of some of these symptoms and co-existing conditions with EDS and HSD.
How does Hypermobility Spectrum Disorder Relate to EDS?
Hypermobility Spectrum Disorder (HSD) is the diagnosis given when people have chronic symptoms related to Generalized Hypermobility (usually chronic pain with or without other complications), but do not have the other signs or symptoms of a heritable connective tissue disorder.
Remember the core defining characteristics of EDS: joint hypermobility, skin hyperextensibility, and tissue friability. Most often, people with HSD have the hypermobile joints but lack one or both of the other features.
HSD is a relatively new diagnosis. It was coined in 2017 when the most recent EDS classification system was published. It is part of an effort to bring validity to the struggles associated with hypermobility, while still identifying them as distinct from EDS and the other genetic connective tissue disorders.
Because the classification is fairly new, people are often misdiagnosed with hEDS when the proper diagnosis is HSD.
The line between HSD and hEDS is blurry and imperfect. Part of the efforts of recent classification systems (in 2017 and upcoming in 2026) is to make this line clearer so the underlying genetic markers and mechanisms of these disorders can be properly identified.
As such, any comprehensive discussion of EDS right now also includes HSD.
Prevalence of EDS
(Stats from https://www.ehlers-danlos.com/prevalence/)
For several reasons, we don’t have a lot of accurate data on how prevalent HSD and EDS are. For example:
Because we don’t yet know the genetic markers or the underlying mechanisms, the line between Generalized Hypermobility, HSD, and hEDS is unclear.
Studies done prior to 2017 used earlier classifications for hypermobility, HSD, and EDS, making their data a little less reliable.
Our understanding of this set of disorders is changing rapidly. It takes a long time for new research to be widely accepted and implemented in the practice of healthcare (think 15 to 20 years).
What we do know is this: EDS is rare. All cases of HSD and EDS combined present in about 1 in every 600 to 900 people.
EDS presents in about 1 in 3,000 to 5,000 people (between 4x and 10x as rare as HSD).
Classical EDS affects about 1 in 20,000 to 40,000 people
Vascular EDS, about 1 in 100,000 to 200,000
The other 10 Subtypes present in less than 1 in 1,000,000 people (yes, less than 1 in a million), with some having only a few confirmed cases in all of medical literature. (These are classified as ultra rare.)
So… What now?
If this general description sounds like you (or a loved one), then the next step is getting your diagnosis correct. I wish I could tell you that would be easy, but it tends to be a challenge.
There are 2 main paths:
1 - Find an EDS-literate healthcare provider to help you. The most common options are a Medical Doctor (MD), Osteopathic Doctor (DO), or Nurse Practitioner (NP). Often, the formal diagnosis of EDS (or another inherited connective tissue disorder) will be made in consult with a Geneticist (usually also an MD).
In some cases, Chiropractic Doctors (DCs) or Physical Therapists can help you along the path, but most Chiropractors lack the training, and Physical Therapists are unable to officially diagnose in the US.
The EDS Society has a directory of providers who have taken their courses:
https://www.ehlers-danlos.com/healthcare-professionals-directory/
2 - Self-diagnose, then build your support team.
As a healthcare provider, this isn’t my favorite option, but it can be unfortunately necessary. (Dr. Google and Dr. ChatGTP are great at telling you all of the things that might be wrong with you, and awful at providing context or empathy. They can’t know more than you tell them, so they’re prone to amplifying the biases and fears of the person using them.)
I’m working on an in-depth article that will help you define the line between HSD and EDS for yourself. That will be available soon.
In the mean time here are some of the most useful and comprehensive resources that I know of:
The most reliable website: The EDS Society’s educational resources
My favorite book on complex hypermobility: Disjointed, edited by Diana Jovin
Note
This post is part of a series that I’m writing in 2026.
I understand that these questions are usually the first steps down a deep (and sometimes urgent) research rabbit hole. If you want to read more before I’m finished with the series, please use the links I’ve listed above for more information. They’re the sources that I’ve found helpful in my own hypermobility research odyssey.
Want to skip the reading and get straight to the part where you feel better?