Arthralgia is joint pain unaccompanied by obvious clinical signs of arthritis or trauma. In most children and adolescents, the affected joint is the knee, hip, ankle, or less commonly an arm joint. Causes of arthralgia include arthritis; systemic disease; tumor; infection; growing pains; transient synovitis of the hip; osteochondroses; ostochondritis dissecans; traction syndrome; chondromalacia of the patella and post-traumatic synovitis. Some pains can be diagnosed with confidence with history, examination, X-ray, and laboratory studies. Other pains are vague, but careful observation of wasting and gait analysis may allow the physician to make a diagnosis.