A pun is to use words humorously.
SOME PUNS ABOUT HEALTH
They called him the king of the dentists because he specialized in crowns.
Psychiatrics like Kentucky Freud Chicken.
The man who impulsively got a cat despite his allergies later realized that it was a rash decision.
SOME JOKES
Wife: Doctor¡ My husband thinks he's a satellite dish
Doctor: Don't worry I can cure him¡
Wife: I don't want him cured I want you to adjust him to get the movie channel.