you don't know how to laugh until you cry

[arethinn]

Why do we sometimes weep when we laugh very hard? Physiologically, I mean. I know both laughter and crying can be emotional responses amounting to "OMG overload I don't know what reaction to have!", but I mean the progression from wracking laughter to tears. Is it just physical stress? Something else?

Comments

[dragonzuela.livejournal.com]

I cry very easily when I laugh. I don't know why, unless I'm so happy that I subconsciously start getting nostalgic about it.

[ninth-myth.livejournal.com]

sometimes i think it might be the brain getting confused/mis-wiring or something like a toddler crying when tired ("too much laughing! cry now!") or maybe it's just a switch so you don't laugh yourself to death.
i think the laughing-til-your-eyes-leak rather than real crying might just be related to face muscles being clenched strangely for a period of time