The eustachian tube connects the throat and middle ear. You have two
tubes, one for each ear. This tube drains fluid from the middle ear into the
throat. It also helps keep pressure in the middle ear equal.
During a cold, sinus or throat infection, or an allergy attack, the
lining of the eustachian tube can swell and block the tube. Air can't move into
or out of the middle ear, so a vacuum effect occurs, which pulls fluid into the
middle ear. The fluid builds up in the ear because it can't drain down the
throat. Germs can grow in the fluid and cause an infection. This condition is
called acute otitis media (ear infection).
An ear infection, or otitis media, is the most common cause of earaches. Although this condition is a frequent cause of infant distress and is often associated with children, it can also affect adults.
The infection in the middle ear (the space behind the eardrum where tiny bones pick up vibrations and pass them along to the inner ear) very often accompanies a common cold, the flu, or other types of respiratory infections. This is because the middle ear is connected to the upper respiratory tract...