Some kids grow up so fast they can feel it! About one-third of all children between ages 3 and 8 experience "growing pains" in their thighs or calves. Although these aches are often attributed to rapidly growing bones, some doctors suspect they may be caused by muscle fatigue, since they frequently occur at night. "When kids finally hop into bed after running around all day, their muscles can have trouble relaxing," says Robert Steele, M.D., a pediatrician at St. John's Regional Health Center, in Springfield, MO. To reduce the pain:

TEACH YOUR CHILD TO STRETCH

If she feels pain in her calves, have her gently flex, then relax her feet a few times. If the discomfort is in her thighs, tell your child to sit on the floor, with one leg stretched out in front of her. Have her slowly swing the other leg behind her, so that the knee is bent and the bottom of her foot almost touches her rear. She should hold the stretch for at least 15 seconds, then repeat the exercise on the other side.

GIVE HER A MASSAGE

Rubbing the areas that hurt can increase healing blood flow to achy muscles; a hot-water bottle can also ease sore muscles. Or wrap a soft, warm cloth from the dryer around painful areas for a few minutes.

CONSIDER MEDICATION

Acetaminophen or ibuprofen may help reduce your child's discomfort. Call the pediatrician if the pain is severe, isolated to one area, or doesn't subside in 24 hours; a joint looks red or swollen, or feels warm to the touch; or your child runs a fever or starts to limp.