You might think that arthritis is something only grandparents
get, but it's a condition that affects people of all ages. Read
on to find out about juvenile idiopathic arthritis (or JIA), a
specific kind of arthritis that can affect people under age 17.
What Is Juvenile Idiopathic Arthritis? Arthritis doesn't affect
young people as much as it does adults, but lots of teens still
get it. Arthritis is an of the synovial (pronounced: suh-no-vee-
ul) membrane, which lines the joints (like the knees or
knuckles). When it becomes inflamed, fluid is produced. The
joints can become stiff, swollen, painful, and warm to the
touch. Over time, inflammation in a joint can damage the
cartilage and bone. "Idiopathic" is a medical word that doctors
use to describe a disease that has no known cause. Juvenile
idiopathic arthritis, which is different from the idiopathic
arthritis that adults get, is the most common kind of arthritis
among kids and teens. Kids usually find out they have this
disease between the ages of 2 and 16. (