A lot of things get called as “growing pains” but merely because there's pain in a developing child does not always mean it is a true growing pain. It is easy to dismiss pain in a growing child as growing pains. A genuine growing pain only occurs at night and never during the day. The discomfort is also in the upper calf muscle and behind the knee. If the pain happens in the daytime and in another place than the back of the leg and knee, then it is not a true growing pain and it is most likely because of something different that must be looked into. Typically, it only happens in younger kids and wakes the child from sleep. There is no history of trauma or any sort of damage to the area that the pain occurs in.
Growing pains are fairly benign and self-limiting, in that they do come right after eventually. However, they can be unpleasant to the child and parents at the time and, most importantly, there are some very serious and rare disorders which may have symptoms much like growing pains, so each case does need to be taken seriously and looked into to rule out these other possible causes. The consequences of missing these uncommon causes of similar symptoms is serious.
The standard management for growing pains is just reassurance of the child. They need to be comforted and helped to get back to sleep. Gentle massage or rubbing of the leg will often help. In some cases medication can be used to help the pain and ease the getting back to sleep. Stretching out prior to going to bed and when the pain happens might also be helpful. Of most importance is education in regards to the nature of growing pains and that it will pass and an evaluation of those possible unusual and serious causes of the discomfort.