> I also don’t know how “bad heart” can mean nausea
It's the same in many other languages. In French, having "mal au cœur" — pain in the heart — can mean that you're nauseous. In Estonian, to "have the heart bad" (using that word order) means the same thing.
It's the same in many other languages. In French, having "mal au cœur" — pain in the heart — can mean that you're nauseous. In Estonian, to "have the heart bad" (using that word order) means the same thing.