There are four factors that may contribute to joint hypermobility.
In a small number of cases, joint hypermobility is associated with a more serious underlying condition. These are often inherited conditions, which parents pass to their children.
Some conditions that can cause joint hypermobility are described below:
Ehlers-Danlos syndrome (EDS) is the name for a group of uncommon conditions that affect connective tissues. There are four main types of EDS, most of which can affect the joints in some way.
Hypermobile EDS, previously known as EDS type III, is a form of the condition many experts now consider to be the same thing as joint hypermobility syndrome (JHS). This is the most common type of EDS and is estimated to affect around one in every 100 to 200 people.
Like EDS, Marfan syndrome affects the body's connective tissues.
The condition can cause hypermobile joints in addition to a number of typical characteristics, such as being tall and having abnormally long and slender limbs, fingers and toes. It can also cause potentially serious problems affecting the heart and eyes.
Osteogenesis imperfecta is a rare condition sometimes known as "brittle bone disease" because it causes fragile bones. Some forms of the condition can also cause joint hypermobility, along with a range of other problems.