Hypermobility spectrum disorders (HSD) are connective tissue disorders that cause joint hypermobility, instability, injury, and pain. Other problems such as fatigue, headaches, GI problems, and autonomic dysfunction are often seen as part of HSD.
What is hypermobility?
Joint hypermobility means that a person’s joints have a greater range of motion than is expected or normal.
Most babies and children are naturally very flexible. Many people become less flexible as they grow, but hypermobility continues into adulthood for some, up to about 20% of people. Being “flexible,” “bendy,” or “double-jointed” is not usually a problem, and for some, like dancers or gymnasts, it is an advantage. Hypermobility that does not cause pain or other symptoms is referred to as “asymptomatic joint hypermobility” and does not need to be treated.
The problem occurs when joints are not just hypermobile but are also unstable. Joint instability occurs when the bones of a joint aren’t held in place securely. This can lead to joint subluxations, dislocations, sprains, and other injuries. Joint instability can cause both acute and chronic pain and interfere with daily life.
Joint hypermobility and/or instability may be a person’s only problem. It can also occur as part of a known syndrome, such as types of Ehlers-Danlos syndromes (EDS), Marfan syndrome, or Down syndrome. The hypermobility spectrum disorders occur when a person has symptomatic joint hypermobility that cannot be explained by other conditions. A person with HSD may have joint instability as their only concern or may have other medical issues as well.
What is a disorder?
A medical disorder is defined as an illness or condition that disrupts normal physical or mental functions. If joint hypermobility causes problems that disrupt normal function, it is a disorder. If joint hypermobility isn’t causing any issues or pain, it is not considered to be a disorder.
What is a spectrum disorder?
A spectrum disorder refers to a condition that has wide variation in both the type and severity of symptoms people experience. For example, people with HSD may have mild or severe joint involvement. They may also experience one, two, or many other symptoms such as fatigue, dizziness, constipation, or headaches, and any of these problems may be mild or severe.