When they say “He/She has 3 days to live” how do they know?

Question

When they say “He/She has 3 days to live” how do they know?

In: Biology

Answer 1

Based off of previous cases.

Doctors can’t perfectly predict when you’ll die, but they can give you a good estimate based on how long all the people who had this disease previously took to die.

Obviously sometimes they’re wrong, either too long or too short, but it’s the best estimate they can give based on the stage of the illness you have and how all the people who had it before you faired.