What happens if something is wrong with your eustachian tube?

Clogged ears. The eustachian tube opens in the back of the nose next to the adenoid and goes up to the middle ear - space behind the ear drum. Fundamentally, dysfunction of the eustachian tube does not allow for aeration and drainage of the middle ear. Symptoms could be as mild as clogging or fullness in the ear to fluid collection with the extreme end of the spectrum causing an ear infection.
Fullness, Clogged. Ear fullness, clogging, hearing loss, can lead to ear infections, pain, See ENT doc to manage.
If blocked. You may have troubling equalizing air pressure in your ears, especially if you fly or dive.