Q: My daughter has been complaining that her legs are aching all the time lately. She's even woken me up in the middle of the night because of the pain. Are these growing pains?

A: About 25 to 40 percent of children experience growing pains, which usually strike during two periods: in early childhood among 3- to 5-year-olds and later in 8- to 12-year-olds.

Contrary to popular belief, growing pains concentrate in the muscles, not the joints. Most commonly, kids experience pains in the front of their thighs, in their calves or behind their knees. While joints affected by more serious diseases are swollen, red, tender or warm, the joints of children having growing pains look completely normal.

Growing pains come and go, and can occur during the day or at night. Some experts think that what we know as “growing pains” could actually be the result of a lower pain threshold to muscle strains caused by normal play. The jumping, climbing and running that active kids do during the day can cause aches and discomfort, especially after a particularly athletic day.

Extremity pains that persist into the day, especially if they limit activity, are not growing pains. If your child's pain is long-lasting—or if you notice a fever, limping, loss of appetite, weakness, tiredness, swelling or redness in one specific area or joint, or any unusual behavior—call your child's pediatrician for further assessment.

Always consult your child's pediatrician concerning your child's health.

For more pediatric health news parents can use, visit our blog: 700childrens.nationwidechildrens.org.

Melissa Winterhalter, MD, is an ambulatory physician at Nationwide Children's Hospital.