Most of the time, decongestants are safe - but not always. They can have serious side effects, usually when given at too high a dose, but sometimes even when given in recommended amounts. Because of this, the American Academy of Pediatrics now advises that children under the age of 6 not be given over-the-counter cold medications.

To unstuff your child's nose, try saline nose drops instead (using a bulb syringe afterward to remove mucus is really effective). It also helps to have a humidifier in his bedroom at night. A menthol rub may be soothing for kids over 2, but check with your doctor first, and apply it only to the back or chest - never under the nose, which can cause breathing problems. Finally, make sure he drinks plenty of fluids, to help keep mucus thinner. And offer lots of hugs and snuggling; the happier and less stressed your child is, the stronger his immune system will be.

Claire McCarthy, M.D., is an assistant professor of pediatrics at Harvard Medical School in Boston. Send her your health questions at Parenting.com/momsquad.