Hypermobility spectrum disorder

Hypermobility spectrum disorders (HSD) are a group of heritable connective tissue disorders where joints are flexible enough to cause problems such as instability and pain. Different forms and sub-types have been distinguished, but it does not include asymptomatic joint hypermobility, colloquially known as double-jointedness, nor does it include Ehlers–Danlos syndromes.

This condition was called "joint hypermobility syndrome" (JHS) until 2017, when it was renamed and subtypes were defined.

There is a strong association between HSD and neurodevelopmental disorders such as attention deficit hyperactivity disorder and autism spectrum disorder.