Hypermobility spectrum disorder

Heritable connective tissue disorder

Hypermobility spectrum disorder (HSD), related to earlier diagnoses such as hypermobility syndrome (HMS), and joint hypermobility syndrome (JHS) is a heritable connective tissue disorder that affects joints and ligaments. Different forms and sub types have been distinguished, but it does not include asymptomatic joint hypermobility, sometimes known as double jointedness. Symptoms can include the inability to walk properly or for long distances, and pain in affected areas. Some people with HSD have hypersensitive nerves and a weaker immune system. It can also cause severe fatigue and some cases cause depressive episodes. It is somewhat similar to other genetic connective tissue disorders such as Ehlers–Danlos syndromes. There is a strong association between HSD and neurodevelopmental disorders such as ADHD (attention deficit/hyperactivity disorder) and ASD (autism spectrum disorder).

Hypermobility spectrum disorders are diagnosed when individuals have symptomatic joint hypermobility but do not meet the criteria for other connective tissue disorders, such as Ehlers–Danlos syndrome. The term "hypermobility spectrum disorder" was coined in 2017 after criteria for hypermobile Ehlers–Danlos syndrome were made more restrictive. In part, this classification change was designed to address the overlap between joint hypermobility syndrome and what was then known as Ehlers–Danlos syndrome, hypermobility type (EDS HT), which some researchers believed were the same condition. While hypermobility spectrum disorders are most analogous to JHS, the 2017 diagnostic criteria for hypermobile Ehlers–Danlos syndrome excludes many people who fit the old criteria, who would instead be diagnosed with hypermobility spectrum disorders. Hypermobility syndrome and hypermobility spectrum disorders do not include people with asymptomatic hypermobility or people with double jointedness but no other symptoms. Hypermobile Ehlers–Danlos syndrome and hypermobility spectrum disorders may be equally severe. The newer term "generalised hypermobility spectrum disorder" includes people with generalised joint hypermobility, often determined using the Beighton Score, and other symptoms. Those who do not meet the Beighton Score criteria may be diagnosed with historical joint hypermobility spectrum disorder, peripheral hypermobility spectrum disorder, or localised hypermobility spectrum disorder.

Prevalence of the condition is unknown, but can be high in those attending musculoskeletal services.