What exactly occurs when you faint from lack of oxygen to make your body start breathing again?



This is a question I don’t know how to ask Google about.

In: Biology

If you spontaneously start breathing again, that means you were probably having a panic attack. When you faint, your panic goes away and your body is able to breathe


Breathing is controlled subconsciously, think of it as autopilot. But if you think about breathing you can consciously control it. If you faint because you held your breath or a panic attack etc and pass out, your subconscious will take over the breathing duties again.

What causes the breathing reflex is a build-up of carbon dioxide, *not* a lack of oxygen. That’s actually a pretty important distinction–it means if you were put into a room which had no oxygen in it, but instead was filled with some other gas that wasn’t immediately fatal (say, nitrogen), you would suffocate without any of the normal warning signs, because no oxygen means your body can’t make carbon dioxide. No CO2, no “I’m suffocating!” warnings.