Synovitis occurs when there’s inflammation in the hip joint. The cause is unknown, but it often occurs after a viral infection. It usually only affects one hip, but it’s possible for swelling and inflammation to spread to other joints.
Most prevalent in children ages 3-8, it is a temporary condition that causes hip pain in children.
Although it’s troubling for parents, this condition usually clears up on its own within a week or two and causes no lasting damage.