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

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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

11 Answers

Anonymous 0 Comments

You need oxygen, which you breathe in, but you breathe out carbon dioxide. If you rebreathe the same air, you’re decreasing the oxygen content with each breath. You’d suffocate yourself.

In a panic attack, the heavy breathing makes you hyperventilate. You get lightheaded from too much oxygen. By breathing into a bag, you’re not getting so much oxygen that you get lightheaded.

Anonymous 0 Comments

You can. Your lungs do not remove 100% of the oxygen in the air with each lungful. You would eventually need to replace the air but it would be good for a few breaths.

Anonymous 0 Comments

When you breathe you take in oxygen. You use the oxygen in your cells and produce carbon dioxide as a waste product which you breathe out.

So without a supply of oxygen, you’ll use it all use in cellular chemical reactions and die as it runs out.

Anonymous 0 Comments

We could….for a little while.

We *do* breathe out some of the oxygen we breathe in, but we do consume some of it. More importantly, we’d also be breathing in our expelled carbon dioxide, which is bad, as you might imagine.

Anonymous 0 Comments

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.

Anonymous 0 Comments

As you breathe you use up oxygen and replace it with toxic carbon dioxide eventually you run out of oxygen and have too much carbon dioxide.

Anonymous 0 Comments

You can for a little while until you use up all the oxygen and then start to suffer from carbon monoxide poisoning

Anonymous 0 Comments

The bag thing doesn’t actually do anything oxygen wise, it’s done mainly to get the person to focus on their breathing to calm them down, focus on taking deeper breathes and stop hyperventilating

Anonymous 0 Comments

There’s a Darwin Award out there for a guy who tried to go to the bottom of a flooded quarry with a trash bag full of air. It’s an educational read.

Anonymous 0 Comments

There’s also the issue of pressure if you are going deep underwater. a bag of air at sea level would get crushed/deflated underwater due to higher pressure. This happens to your lungs too. When scuba diving, the tanks have very compressed air, and the regulator reduces the pressure (but still more than surface pressure) to keep your lungs inflated.