system
Given the following post, respond as if you're commenting on Reddit:
human
What goes on in the body while a person is in a coma?
gpt
Basically, your heart keeps beating, your lungs keep breathing, your blood vessels keep things moving. The things that are absent are patient sensations and thoughts. Your brain is inoperative/damaged and essentially shuts down everything you don't need to stay alive. It can happen from a variety of different things, but brain damage is one of the more common things to cause it. The body will die however, without treatment and nutrients. So a person going into a coma won't last long without being in a hospital.

TL;DR: Think of it as a running car with everything working, but the driver is asleep with the car in park. The car will keep running until gas runs out.