Dear Parent, I m sorry to hear that your child is having this problem with his left leg. Firstly, to reassure you, if the x-rays were normal and the child has not had a accident/injury to the leg, the most common problem that causes hip and pain in the leg for children is Irritable Hip or Transient Synovitis . This usually occurs after a viral infection and causes the child to have pain in their hip or knee due to a secondary reaction to the body fighting off a viral infection. This does usually get better with simple analgesia, rest and time. If the x-rays were normal, this is probably what your local doctor thought the problem was. However, there are some more serious causes for this problem, and if it is not improving after 7-10 days, you should go back to your doctor for more investigations. If your child is having pain in the leg which is waking him at night, this should be looked into more carefully immediately. Equally, if your child has fever, or the joint or muscle is red, hot and inflamed, this can be due to infection in the joint/muscle and should also be treated immediately. Other joint problems should have been ruled out with the x-ray, but you could always get a second opinion on the x-rays if you remain concerned. If the problem is not resolving, some simple blood tests to look at his Full Blood Count, Inflammation Markers and Infection Markers could well provide an answer for you, you could request these from your local doctor. I hope this helps you with your concerns. If you have any further questions, do not hesitate to ask and we will try to help. If you found this helpful, please leave a rating!