By: Dr Zaid Matti
Musculoskeletal Medicine Specialist
In clinical practice, many patients carry the diagnosis of fibromyalgia — often after years of chronic widespread pain, fatigue, and functional limitations. However, careful evaluation sometimes reveals that the underlying cause may actually be related to hypermobility spectrum disorders (HSD) or hypermobile Ehlers-Danlos Syndrome (hEDS). These patients are frequently misdiagnosed, leading to delays in appropriate treatment. Recognising the overlap between these conditions is crucial for accurate diagnosis and effective, targeted management.
Understanding the Two Conditions
Fibromyalgia: A Central Sensitisation Disorder
Fibromyalgia is characterized by:
- Chronic widespread musculoskeletal pain
- Profound fatigue
- Sleep disturbances
- Cognitive dysfunction (“fibro fog”)
- Headaches, irritable bowel symptoms, and generalized hypersensitivity
At its core, fibromyalgia is a disorder of central pain processing — involving heightened excitability of the central nervous system and altered pain perception. Research has identified neurochemical imbalances such as elevated substance P, altered serotonin and norepinephrine levels, and functional changes in pain modulation centers of the brain. [Clauw DJ, 2014; Wolfe F et al., 2010]
Hypermobility Spectrum Disorders and Hypermobile Ehlers-Danlos Syndrome
Hypermobility disorders are heritable connective tissue disorders characterized by:
- Joint hypermobility (generalized, localized, or historical)
- Chronic musculoskeletal pain often related to joint instability and microtrauma
- Recurrent subluxations or dislocations
- Easy bruising or soft tissue fragility
- Dysautonomia (postural tachycardia syndrome, orthostatic intolerance)
- Gastrointestinal dysmotility
- Fatigue and exercise intolerance
Connective tissue laxity underpins the mechanical vulnerability seen in hypermobility disorders. Many patients with HSD or hEDS develop chronic pain syndromes that resemble fibromyalgia due to secondary central sensitization. [Castori M et al., 2017; Tinkle B et al., 2017]
The Overlap: Why the Confusion Happens
These two syndromes often overlap substantially:
| Symptom | Fibromyalgia | Hypermobility Spectrum Disorders |
|---|---|---|
| Chronic widespread pain | Yes | Yes |
| Fatigue | Yes | Yes |
| Sleep disturbance | Yes | Yes |
| Autonomic dysfunction | Sometimes | Frequently |
| Gastrointestinal complaints | Sometimes | Frequently |
| Joint hypermobility | Rare | Core feature |
| Joint subluxation | No | Frequently |
| Skin hyperextensibility | No | Sometimes |
| Family history | Sometimes | Frequently |
everal studies have shown that between 40% and 50% of fibromyalgia patients meet criteria for joint hypermobility. In many cases, joint laxity and mechanical instability drive chronic nociceptive input, which over time can lead to central pain amplification — mimicking fibromyalgia. [Sendur OF et al., 2007; Langevin HM et al., 2020]
Systemic Manifestations: Beyond Joints and Pain
While hypermobility is primarily thought of as a joint disorder, it is actually a multisystem condition involving several organ systems.
Cardiovascular Involvement
Many hypermobile patients experience:
- Postural Orthostatic Tachycardia Syndrome (POTS)
- Orthostatic intolerance with dizziness or fainting
- Mitral valve prolapse
- Aortic root dilatation (rare, but important in some EDS subtypes)
Careful cardiovascular evaluation, including echocardiography and autonomic testing, may be warranted, particularly in those reporting palpitations, syncope, or exercise intolerance. [Shibamura-Fujiogi M et al., 2020; Hakim AJ et al., 2017]
Gastrointestinal Manifestations
Connective tissue fragility can also affect the gastrointestinal system, leading to:
- Gastroesophageal reflux (GERD)
- Irritable bowel syndrome (IBS)
- Gastroparesis (delayed gastric emptying)
- Visceral hypersensitivity
These symptoms often mimic functional gastrointestinal disorders but may have a structural basis in connective tissue dysfunction. Targeted evaluation by a gastroenterologist familiar with hypermobility syndromes is important for accurate management. [Zeitoun JD et al., 2013; Fikree A et al., 2014]
The Importance of Specialist Evaluation
Given these systemic manifestations, a multidisciplinary approach is often essential. Input from cardiology and gastroenterology specialists familiar with hypermobility-related conditions can identify comorbidities early, tailor management, and improve long-term outcomes.
The Emerging View: A Shared Spectrum
Many experts now view fibromyalgia and hypermobility-related pain as part of a continuum — where connective tissue laxity provides a structural vulnerability, and central sensitization develops as a secondary phenomenon. This perspective emphasizes the need to address both mechanical instability and abnormal pain processing. [Rombaut L et al., 2015; Hakim AJ et al., 2017]
Treatment Approach: Individualised & Mechanism-Based
| Target | Interventions |
|---|---|
| Joint instability | Proprioceptive physiotherapy, bracing, activity modification, orthobiologics support |
| Central sensitization | Cognitive behavioral therapy, graded exercise therapy, sleep optimization |
| Dysautonomia | Salt/fluid loading, compression garments, autonomic rehabilitation |
| GI dysfunction | Targeted gastroenterology management, dietary modifications |
| Nutritional support | Vitamin C, magnesium, omega-3 fatty acids, and other adjunctive measures [Rowe PC et al., 2021] |
Conclusion
In my practice at NZ Musculoskeletal & Regenerative Medicine Centre, many patients previously diagnosed with fibromyalgia are ultimately found to have undiagnosed hypermobility spectrum disorders. Accurate diagnosis allows us to shift away from generic symptom control and toward targeted treatment addressing both mechanical instability and central sensitisation. This multidisciplinary, mechanism-based approach offers many patients an opportunity for meaningful, long-term improvement.
References
- Clauw DJ. Fibromyalgia: a clinical review. JAMA. 2014;311(15):1547-1555.
- Wolfe F, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res (Hoboken). 2010;62(5):600-610.
- Castori M, et al. Ehlers-Danlos Syndrome, Hypermobility Type: An Underdiagnosed Heritable Connective Tissue Disorder with Mucocutaneous, Articular, and Systemic Manifestations. ISRN Dermatol. 2012:751768.
- Tinkle B, et al. Hypermobile Ehlers–Danlos syndrome: Clinical description and natural history. Am J Med Genet C Semin Med Genet. 2017;175(1):48-69.
- Sendur OF, et al. Fibromyalgia in hypermobility syndrome: prevalence and clinical characteristics. Rheumatol Int. 2007;27(11):1013-1017.
- Langevin HM, et al. Connective tissue and fibromyalgia: more than skin deep. J Bodyw Mov Ther. 2020;24(1):19-22.
- Rombaut L, et al. Musculoskeletal complaints, physical activity and health-related quality of life among patients with hypermobility type Ehlers-Danlos syndrome. Disabil Rehabil. 2015;37(9):720-726.
- Hakim AJ, Grahame R. A simple questionnaire to detect hypermobility: an adjunct to the assessment of patients with diffuse musculoskeletal pain. Int J Clin Pract. 2003;57(3):163-166.
- Rowe PC, et al. Orthostatic intolerance and its relationship to chronic fatigue syndrome and fibromyalgia. J Clin Med. 2021;10(21):5178.
- Shibamura-Fujiogi M, et al. Cardiovascular autonomic dysfunction in patients with hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders. Am J Med Genet A. 2020;182(10):2312-2319.
- Fikree A, Chelimsky G, Collins H, Kovacic K, Aziz Q. Gastrointestinal involvement in the Ehlers-Danlos syndromes. Am J Med Genet C Semin Med Genet. 2017;175(1):181-187.
- Zeitoun JD, Lefevre JH, de Parades V, et al. Functional gastrointestinal disorders in Ehlers-Danlos syndrome and Marfan syndrome: a prospective study of 50 patients and review of the literature. Neurogastroenterol Motil. 2013;25(9):e583-e588.
