Have you ever been called a juvenile? It's actually not an insult — it just
means that you're a kid.
arthritis, or JRA, is called that because it's different from the arthritis that
adults get. Arthritis
causes pain and swelling of the joints. JRA makes it hard for kids who have it to
move their joints. JRA is an autoimmune
disease. That means the immune system attacks healthy cells by mistake. Kids with
JRA take medicine and need to keep their joints moving.