Your child cries out in the middle of the night that his leg hurts. You ask the doctor the next day, and she says it's probably growing pains. Growing pains aren't just a concept; they're a physical symptom, and they can be quite painful.

In the September issue of Wondertime magazine, Dr. Jack Maypole, a Boston pediatrician, offers these tips on growing pains:

 --Growing pains commonly diagnosed as pains or aches that come and go, usually in the muscles of the calves and thighs or behind the knees, Maypole says.

--They occur in about 25 to 40 percent of all children, peaking at ages 3 to 5 and 8 to 12.

 --Pain can be mildly irritating or severe and can last for minutes to several hours.

--Maypole recommends having the child stretch and/or rubbing his legs after periods of intense activity to avoid these pains. If they come anyway, a pain reliever (acetaminophen or ibuprofen)  can be given. But if your child needs it for several nights in a row, it's probably time to visit the doctor.

--A heating pad can help, but use it carefully.

--Another technique Maypole says often works: Help your child use visualization techniques, such as imaging his pain "hurtling into outer space," or thinking about a place or activity he likes.

--The good news: Maypole says that for most children, growing pains begin to go away as adolescence begins.