system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we get a feeling in our chest/stomach when we have sad/bad thoughts?

The experience itself is hard to explain, almost like a hollow feeling.
gpt
This is an evolutionary response to stressful situations. Basically your body pumps out adrenaline while at the same time pulling blood from your inner organs to feed to your muscles. This is part of the fight-or-flight response of your body and prepares it to do either.