Muscle aches have many possible causes. Some common ones are overuse, tension, and injuries such as a strained muscle. An infection such as the flu can cause muscle aches. Or the aches may be caused by some medicines. Muscle aches may also be a symptom of a health problem. Myalgia is the medical term for muscle aches.
Your child's doctor will do a physical exam and ask questions to try to find what is causing your child's pain. Your child may also have tests such as blood tests or imaging tests like X-rays. These can help find or rule out serious problems.
The doctor has checked your child carefully, but problems can develop later. If you notice any problems or new symptoms, get medical treatment right away.