How would enlarged adenoids cause a runny nose?

Answer:
Given the adenoids' location in the very back of the nose (against the back wall in fact), it is immediately behind the eustachian tube. If the adenoids become large, they can physically block the eustachian tubes, resulting in great difficulty in getting the ears to pop (if at all) resulting in a persistent clogged ears.

Furthermore, given the nose normally produces as much as several liters of mucus/fluid to humidify and warm the air that is breathed, if the adenoids are large, all that mucus backs up in the nose as it is not able to easily drain into the throat. This back up can result in symptoms of rhinorrhea (runny/snotty nose), allergies, and colored nasal drainage from the front of the nose.

Not only do large adenoids prevent normal mucus production from flowing into the throat, it also prevents air movement as well causing symptoms of nasal obstruction and congestion as well as a nasal sounding (hyponasal) speech.
First answer by ID1357255287. Last edit by ID1357255287. Question popularity: 1 [recommend question].