Eli5: Why does an IV of fluids make you feel so much better than drinking the same amount of fluids?

Question

I know it goes into your body faster but an IV seems to make me feel miraculously better even if I drink fluids and wait.

In: 21

Answer 1

Your osmoreceptors that detect fluid balance in your brain quickly stop panicking and thus stop telling other things in your body to panic so they then also calm down, making you feel better.