Otitis media with effusion is fluid in the space behind the eardrum (middle ear). This condition occurs when a blockage of the tube that connects the throat and middle ear (eustachian tube) prevents fluid from draining normally out of the middle ear space and prevents air from entering the middle ear.

Fluid in the middle ear may:

• Cause sounds to be muffled.
• Cause mild discomfort. The pain usually increases with changes in atmospheric pressure, such as increasing cabin pressure when an airplane is coming down to land.
• Create an environment for the growth of viruses or bacteria, which may cause infection. However, fluid in the middle ear does not always mean that an infection is present.

The body usually reabsorbs the fluid behind the eardrum within weeks. As the fluid is reabsorbed, hearing gradually returns to normal. If fluid is still present in the middle ear after a few months, or is accompanied by prolonged fever and other symptoms, antibiotic treatment may be necessary.