system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come people get brain damage after 1-2 minutes of oxygen starvation but it’s also possible for us to hold our breath for 1-2 minutes and not get brain damage?
gpt
Brain damage happens when the *brain* is starved of oxygen.  When you hold your breath, your heart keeps beating and blood keeps flowing, bringing oxygen to your brain.

Hypothetically there's an amount of time where if you could hold your breath for that long, you *would* start to deprive your brain of oxygen, as you deplete the oxygen left in your lungs and blood stream.  Realistically you'll pass out and begin breathing again before you get to that point though.