Occasional knee pain may be caused by physiological factors such as growing pains, or by diseases such as meniscus injuries and rheumatoid arthritis, and the cause should be identified in a timely manner. 1. Growing pains: Healthy children between the ages of 2 and 12 may experience recurrent, intermittent pain in the lower limbs, mainly around the knee joint and the anterior side of the lower leg. This is due to the pulling of the periosteum. Generally, there is no need to do any treatment, and most of the symptoms can disappear with the maturity of bone development. 2. Meniscus injury: If the lower limbs are overly active for a long time or when the movement is not proper, it may lead to meniscus injury of the knee joint, which is usually manifested as pain when walking or exercising, and may also show symptoms such as limitation of joint movement and sudden weakness. 3. Rheumatoid arthritis: rheumatoid arthritis is usually caused by streptococcus and other infectious factors, which will trigger edema in the tissues around the knee joint, resulting in symptoms of knee joint pain. In addition to the above reasons. Trauma and epiphysitis may also cause occasional knee pain. If occasional knee pain occurs and is difficult to be relieved on its own, it is recommended to consult a doctor in a timely manner to clarify the cause of the problem and treat it accordingly.