The eustachian (say “you-STAY-shee-un”) tubes connect the middle ears camera.gif to the back of the throat. The tubes help the ears drain fluid. They also keep air pressure in the ears at the right level.
When you swallow or yawn, the tubes open briefly to let air in to make the pressure in the middle ears equal to the pressure outside of the ears. Sometimes fluid or negative pressure gets stuck in the middle ear. The pressure outside the ear gets too high. This causes ear pain and sometimes trouble hearing.
Swelling from a cold, allergies, or a sinus infection can keep the eustachian tubes from opening. This leads to pressure changes. Fluid may collect in the middle ear. The pressure and fluid can cause pain. You also can have ear pain from changes in pressure while you are flying in an airplane, driving up or down mountains, or scuba diving. Fluid in the ear can lead to an infection (acute otitis media). Young children have a high risk of ear infections, because their eustachian tubes are shorter and more easily blocked than the tubes in older children and adults