Mr. Zhang called to ask: my child is 8 years old, often said his leg pain, but we usually do not see him bumped. A few days ago, we took our child to the community hospital, but no cause was found. What is wrong with my child’s leg pain? Doctor’s answer: According to your description, the cause of your child’s leg pain is not in the leg, you need to take your child to a large hospital for further examination to confirm the diagnosis. In clinical practice, many children are unable to tell the exact cause of their leg pain, and the doctor is unable to find out the cause from the leg. In most cases, the leg pain is likely to be in the hip joint. During childhood, children do have more hip-related pathologies than other parts of the leg, such as congenital hip dislocation and ischemic necrosis of the femoral head. In particular, there is transient synovitis of the hip joint, which is an acute inflammation of the hip joint caused by a nonspecific inflammatory condition. The disease mostly occurs in children aged 7 to 10 years old, who suddenly develop pain in the legs and hips (children often complain of leg pain), and the affected limbs are afraid to bear weight, limp, or even move around. The affected limb is often in an inward and internally rotated flexed position, and may also have fever, cough, and mental lethargy. About two weeks before the onset of the disease, children often have a history of upper respiratory tract infection, dysentery, etc., but no obvious history of trauma. Laboratory tests may reveal leukocytosis and accelerated blood sedimentation, etc. On X-ray, there may be a widening of the soft tissue shadow of the hip capsule and an arcuate elevation, especially above and below the joint. In addition, we can find changes such as widening of the joint space and mild outward displacement of the femoral head, but no bone destruction. If your child is diagnosed with a transient synovitis of the hip joint, it is recommended that he or she rest in bed, should not bear weight, and should be treated actively according to medical advice.