system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5. How do doctors know when someone is about to die and they say something like, "Call the family and tell them it's coming."
gpt
You start breathing weird is the simplest way to put it.

Most commonly it's Chyene-Stokes respiration (alternating periods of shallow fast breathing and slow breathing).

There is also what is called agonal breathing--this is a very distinctive pursed lip gasp that looks like a dying fish gasping on land.

And there is times where you notice a patient going into a long sustained period of rapid breathing.

The respiratory control center of the brain stem is generally the last thing to fail in the body, but when that starts to go. It's not long until the entire body goes with it.