system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:When somebody who is terminally ill decides to 'stop fighting/let go' and passes away soon after, what actually happened to them physiologically? Or is this somewhat of a myth?
gpt
Fighting a serious disease is hard work.  When you are fatigued, in pain, drugged, and depressed, keeping up with diet, exercise, hygiene, medication, and invasive medical treatment is often beyond what you can handle.  When you stop fighting, you stop doing these things that are keeping you alive.

You also have some confirmation bias here.  We don't remember the times when people give up and didn't die.