system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the urge to vomit a common reaction when you smell something horrible?
gpt
Vomiting is a reaction meant to expel something from your stomach that is hazardous. So if you taste something that your body believes is poisonous, it will trigger a vomiting reaction to protect you.

But smell and taste are closely linked (in fact, the process of tasting includes smell, which is why your taste sense is dulled when you have a cold or otherwise can't smell). Since these senses are so closely linked, the vomit trigger that is linked to taste can also be triggered by smell.