Juvenile idiopathic arthritis is the newest and preferred terminology to describe chronic arthritis in children. Idiopathic means unknown cause or spontaneous origin. The disease is also sometimes referred to as juvenile arthritis (JA) or juvenile rheumatoid arthritis (JRA). Children under 17 years of age who develop inflammation in a joint (usually with swelling and/or pain and/or morning stiffness) that lasts longer than six weeks usually have JIA. There are seven different types of JIA, and the pattern of arthritis and the short-term and long-term effects of each type are different. We do not know the cause of any of the types of JIA. If the arthritis is associated with another disease such as lupus, dermatomyositis, inflammatory bowel disease or even leukemia, the arthritis is not known as JIA.