Children who get up in the morning and suddenly have leg pain and cannot walk may be caused by trauma, growing pains, femoral head necrosis, malignant tumors and other reasons. Trauma bandage, surgery to remove the tumor and other causative treatments are available. 1. Trauma: check whether there is any obvious trauma immediately, ask the child whether there is any bump when playing recently, palpate the joints to check whether there is any swelling and pain, etc. to determine whether it is caused by trauma. If there is a wound, it needs to be bandaged, and if there is a suspected fracture, it is necessary to go to the hospital for fracture repositioning and immobilization. 2. Growing pains: the most common manifestation is no pain during the day, but pain at night, which may lead to the inability to walk in the morning, and this kind of growing pains is difficult to have a clear diagnosis during the physical examination, and can be diagnosed by exclusion. Growing pains are a healthy physical manifestation of the child. 3. Necrosis of the femoral head: early children may have obvious differences in walking, such as falling when walking uphill, or walking too much, running and jumping with severe pain, at this time, we should go to the pediatric orthopedic department for a clear diagnosis, targeted treatment. 4. Malignant tumors: for example, osteosarcoma, prevalent in children, will lead to bone pain in children so that he affects walking. Need to go to the regular hospital for surgery, chemotherapy. If the pain is not relieved or even aggravated, we should go to the hospital in time to determine the cause of the disease and standardize the treatment under the guidance of the doctor.