What is Eustachian Tube Dysfunction?
Eustachian tube dysfunction (ETD) means that the Eustachian tube is blocked or does not open properly. Air cannot get into the middle ear. Therefore, the air pressure on the outer side of the eardrum becomes greater than the air pressure on the inner side of the eardrum.
The most common causes of Eustachian tube dysfunction are excessive mucus and inflammation of the tube caused by a cold, the flu, a sinus infection or allergies.