Hypermobility is a misleadingly simple term that means ‘excessive mobility of joints’. It is sometimes also known as ‘joint laxity’.

This term is not as simple as it may seem. To start with, we need to understand the normal range of joint movements and we need to be able to say when a person’s joints move beyond that normal range. This depends on the age of the patient: children’s joints are naturally more mobile than adults’ joints, for example.

Some people have hypermobile joints without that causing them any problems. Sometimes we find this trait running through their family. Different terms are used for this, such as ‘familial benign hypermobility’. Often this hypermobility is restricted to one set of joints, like the fingers.

Some people have hypermobile joint in the presence of other problems. We recognise different patterns of problems that suggest an underlying ‘hypermobility syndrome’. Such syndromes are often inherited, giving rise to the term ‘familial hypermobility syndrome’. This is not in itself a diagnosis but a description.

The challenge is to ask the question “What familial hypermobility syndrome?” and to identify the correct diagnosis. Only then is it possible to consider the prognosis and most appropriate management.