Hi, Growing pain is the most common cause of limb pain in children. To ascertain the cause, we need few more details. Did this follow any fall or trauma? pain on both limbs? pain during walking or playing only? day or night? any swelling or pain to touch? Growing pains are commonly mild-moderate, usually occur bilaterally, more towards evening and night, but never occur on a joint and not associated with swelling / tenderness. Try simple analgesics like paracetamol or ibuprofen for 3 days- if getting better leave it or kindly get him examined with your doctor to see whats going on. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Muhammed Aslam TK, Pediatrician