Usually the first thing that pops in my head is a cleric class or a religious person of faith in fantasy rpg's.
Both having extraordinary or specialize greatly on healing abilities or knowledge of mending wounds depending on what genre and magic system your dealing with.

Cause if it's not one of those two things then it's probably this guy:
https://www.youtube.com/watch?v=t348e24vDyA

He's not even a doctor. He's a man of science first and a unlicensed medical professional second.