Children’s knee pain may be a normal physiological phenomenon, or it may be caused by knee injuries, arthritis or synovitis. 1. Normal physiological phenomenon: Due to the faster growth rate of children, the growth of muscles and bones will produce a more obvious difference, when the muscle growth rate is faster, it can pull to the joints, thus causing pain. 2. Knee injuries: When children are running, jumping or in the process of activities, due to the lack of attention to self-protection, it may cause knee meniscus, tendons, ligaments and other injuries, resulting in pain symptoms. 3. Arthritis or synovitis: When children suffer from arthritis or synovitis, the inflammatory substances can cause irritation to the nerve tissues, resulting in redness, swelling, heat and pain in the knee joint. Children’s knee pain may also be related to other causes, parents should be vigilant and take their children to the hospital as soon as possible to clarify the cause of the disease, which is conducive to targeted treatment, so as to achieve good results.