system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does anxiousness make us feel nauseated?

Like, for example, if you eat something spoiled or otherwise gross you might feel nauseous because your body wants it out of your system. Same thing goes for if you eat way too much. I don't see a reason why vomiting would help in the event of nausea, nor do I see how nervousness or anxiety would be able to manifest as the physical symptom of nausea.
gpt
When you are afraid, including anxious, your body shuts down systems that it won't be needing to either run away from or fight the thing you are afraid of (like a predator.) So it basically halts/slows digestion and this gives you an upset stomach because food isn't digesting like it should. This is especially harmful in today's world because the system was developed to be very short term - you run away from that tiger and either you make it or you dont but you are only running awa/fighting for a short time. In today's world as we are anxious for long periods of time it wrecks havoc on our digestive system.