Growing pains in children are a benign self limiting problem, but a couple of potentially serious health problems can have similar symptoms to growing pains, so they do need to be taken seriously. The classic description of growing pains is pain behind the knee that most occurs at night, usually early in the evening. The pain is usually in the upper calf muscle and wakes the child from sleep. They can be quite distressed by this. The treatment is just reassurance, gentle massage and stretching. Anti-inflammatory drugs are reserved for the most serious cases.
If the pain occurs at times other than early evening and the pain is in the bone or joints, then a further investigation is needed, as pain at this time and places is not the typical growing pains. Juvenile arthritis and a bone tumor are two are possibilities that need investigating.