Arthritis is often associated with older people, but it can also affect children. In the UK, about 15,000 children and young people are affected by arthritis.
Most types of childhood arthritis are known as juvenile idiopathic arthritis (JIA). JIA causes pain and inflammation in 1 or more joints for at least 6 weeks.
Although the exact cause of JIA is unknown, the symptoms often improve as a child gets older, meaning they can lead a normal life.