system
Given the following post, respond as if you're commenting on Reddit:
human
Why do we breathe irregularly while crying?

I just don't get it. Why do teary eyes and a runny nose cause irregular breathing?
gpt
Teary eyes and a runny nose don't cause irregular breathing, but they share a common cause. 

Sobbing is a form of hyperventilation, which can happen in cases of extreme stress. The more stressful the situation, the more likely you are to hyperventilate. We don't usually sob while watching sad movies or when crying "happy tears" because those situations are not particularly stressful, compared to say, a bad break-up where you are so stressed out you're literally losing your mind. Hyperventilation is believed to be a psychological phenomenon rather than a physical one, so it really is only dependent on your mental state.