The House M.D. episode in which House gives three diagnostic lectures is “Three Stories.”
“Three Stories” is the 21st episode of the first season and uses a lecture framework to present three medical cases to students. The structure allows the episode to move between House’s teaching session and important details from his past.
The episode is especially significant because it reveals the origin of House’s chronic leg pain and explains why he walks with a cane. Its nonlinear storytelling also shows how easily medical assumptions can lead doctors toward the wrong diagnosis.
“Three Stories” received major critical recognition and won the Primetime Emmy Award for Outstanding Writing for a Drama Series. It is often cited as one of the defining episodes of the show.