system
Given the following post, respond as if you're commenting on Reddit:
human
What causes the pain in your torso when you're very sad, emotionally hurt, and/or heartbroken?

I've been wondering this since I was little, but only now thought to ask someone that might be qualified to give a real answer.

For me, when something is overwhelmingly sad or upsetting, there's a sort of internal pain in the general area of my chest.  My (utterly uneducated) theory is that this is the basis for the somewhat nonsensical link people make between the heart - which, as far as I know, is purely a muscular, mechanical organ - and emotions - which obviously originate in the brain.
gpt
A contraction of your muscles, which is normally involuntary. Assuming you mean the tightness in the upper chest and lower throat yes?

I am not a doctor, biologist or anything remotely close, but at a guess, your brain is overwhelmed by the emtion you are feeling which causes a release of some chemical into your blood to prepare certain muscles for a reaction. Somewhat similar to a fight or flight responce with adrenaline?