Knee pain may be caused by trauma synovial inflammation and other predisposing factors, to relieve pain, the cause needs to be identified. 1. Growing pains: In the course of growth and development, rapid growth of the child may cause pain in the muscles and joints, which often occurs at night just before going to sleep, and everything is normal during the day. To relieve such a situation, you need to give him a hot compress on this area every night before going to bed. 2, synovitis: the child has the symptoms of cold and fever, that is, the presence of bacterial, viral infection, which can easily lead to serious inflammation of the joint, there may be fluid, but this disease is often self-limiting, we do not need special treatment, let the child pay attention to rest, local hot compresses can be. 3, if the child has ever had a blow injury in this area, it may lead to effusion or ligament and joint capsule bone damage, in this case, you need to go to the orthopedic department to take a film, if there is a problem, you need to play a cast or surgery to repair, if there is no problem pay attention to hot compresses every day, pay attention to rehabilitation exercises can be. Therefore, knee pain is caused by many reasons, and the cause must be identified and given the appropriate treatment for the symptoms.