Sophie McDonald, of Green Island School, asks :-

Why do we get earache?

Patrick Dawes, an Ear, Nose and Throat Surgeon at the Universary of Otago's Medical School, responded.

The ear has three parts: an outer ear canal, an air filled middle ear, and an inner ear. The ear drum detects and transmits sound waves best when the air pressure in the middle ear is the same as that in the outer ear. The middle ear joins the back of the nose by a tube, called the Eustachian tube. This is usually closed, but opens when you swallow or if you pinch your nose and blow air up the tube. Opening the Eustachian tube allows the pressure in the middle ear to be the same as the outer ear.

Earache can be caused by changes in pressure across the eardrum. When flying in an aeroplane high in the earth’s atmosphere, the air pressure drops. If the pressure doesn’t stay the same on both sides of your eardrum you may get earache. So, when the cabin pressure drops, air from the middle ear needs to escape along the Eustachian tube to equalise the pressure on both sides of the eardrum. We can help this by swallowing – you may feel your ears “pop” as the pressure suddenly equalises. When the aeroplane descends the air pressure in the aircraft starts to rise and pushes the eardrum inwards; this can be particularly painful. Once again, swallowing helps to equalise the pressure across the eardrum (which is why you are sometimes given a lolly to suck). Babies cannot open their Eustachian tube as easily and so may be more likely to get earache as the aeroplane descends.

There are other causes of earache too such as infection in the ear. Sometimes, we can feel earache even though our ears are healthy. This is because the same nerves that supply the ear also supply the upper back teeth and parts of our mouth and pain signals from these places can fool our brain into thinking we have earache.