Why couldn’t we just use a bag and reuse the air we breathe when underwater

Question

I’ve always wondered this since I was a child, and I see people use bags to rebreathe the air they have in their lungs for panic attacks, which only increases my curiosity.

In: Biology

Answer 1

i dont know why for the panic attack one, but when you breath out air you dont breathe out oxygen, you release carbon dioxide, which from personal experience, makes you feel sick when breathing in.