A: Vivian, it's usually only the takeoff and landing that can be painful for young children's ears, when the air pressure in the cabin is changing.

Why do babies' ears hurt when cabin pressure changes? Our ears naturally adjust to changes in air pressure through our Eustachian tubes, which connect the middle ear, behind the ear drum, to the back of the nose and throat. During takeoff and landing, you might feel the pressure and popping in your ears, and you might yawn, chew gum or swallow. This helps your Eustachian tubes open up so your ears adjust to the pressure. Babies, however, have narrower Eustachian tubes, and sometimes they don't open up as easily to equalize the pressure. This can cause pain and lead to fussiness and crying.

Some babies experience ear pain on airplanes and others don't. A good way to help prevent it is to have your baby breastfeed, drink from a bottle or cup or suck on a pacifier during takeoff and landing. (Remember that it's safest to have baby strapped into her carseat in her own airplane seat at these times.) Children older than 3 years can chew on gum.

Make sure that both you and your baby drink plenty of fluids during the flight because the dry air on planes tends to dehydrate most people a little. Your baby is more likely to experience ear pain if she has nasal congestion from a cold or allergies, which can cause swelling of the Eustachian tubes. If that's the case, ask the pediatrician whether you should give your baby an antihistamine/decongestant for the flight.