system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does pressure on the ears go away if you swallow?
gpt
Inside our middle ear, there's a tube called the *Eustachian tube* that connects it to the back of our throat. Swallowing opens that tube, letting air flow between your middle ear and the outside, letting the pressure equalize.

This is why yawning sometimes helps, as does plugging your nose and blowing out hard through your nose (the *Valsalva maneuver*).