Every time I go to the clinic, I always find that more children (10-15%) are brought to the clinic by their parents because of unexplained leg pain, and looking at the parents’ anxiety and not being able to get a number, I really can’t bear not to add a number. However, after seeing them, I found that most of them had no problems, and the parents lamented that they should have known better than to rush all the way here (some from other provinces). Therefore, I feel it is necessary to introduce you to the problem of leg pain in children here. First of all, it is important to clarify whether the leg pain that the child is describing is a disease or not! For example, when a child goes to bed at night with too much activity during the day, he or she will report leg pain, which is caused by the stimulation of acidic metabolites produced and gathered in the muscles and joints of the lower extremities during the day, plus the monotony of the indoor environment, which makes the child’s attention focused, so the symptoms are more obvious. After a night’s rest, the symptoms often disappear the next morning. This is a typical physiological fatigue (the same as fatigue after work and activity of adults), accounting for the majority of outpatient visits. In this case, only local heat is needed, soothing massage and bedding warmth can be applied, and no pain medication is needed. The following is a discussion of growing pains, a common concern among parents. Growing pain is a benign discomfort in the lower extremities that lacks a specific cause. It may be caused by the rapid growth of the bones, which leads to strain on the surrounding muscles and ligaments and compression of the joints. 15-30% of children have this phenomenon, which occurs mostly during the child’s rapid growth period. The child’s general condition is good and there is neither tenderness nor limitation of joint movement in the lower extremities. This is a benign, self-limiting condition that requires only hot compresses and pain medication and calcium supplements depending on the situation. However, if there is a change in the clinical picture, the child should be taken to a doctor. Parents should also be reminded that lower extremity pain can also be the result of an intrinsic disease, although it is much less common. In this case, the child’s leg pain is often confined rather than vaguely localized to both lower extremities, often interfering with movement and occasionally leading to a limp. It is important to note any changes in the child’s general health, any tenderness in the extremities, any limitation in the range of motion of the joints, and the presence of deformities and joint stiffness in the extremities. At this time, the child should be brought to the clinic and may require x-rays and necessary laboratory tests. Parents should pay attention to the fact that pain in the lower limbs at night may also be caused by tumors, such as benign osteoid osteoma and malignant osteosarcoma, etc. This pain is limited, often complicated by local soft tissue masses, and progressively worsens.