Dr. Gregory House repeatedly says, “Everybody lies,” in House M.D.
The phrase summarizes House's belief that patients, families, and even fellow doctors may conceal information or present an incomplete version of events. He uses that assumption as a diagnostic tool: instead of accepting a patient's account literally, he looks for overlooked behavior, hidden exposures, and motives that could explain the symptoms.
“Everybody lies” became one of the show's most recognizable lines and is closely associated with House's cynical worldview. It does not mean that every statement is knowingly false in the same way. The series often shows that people omit facts because they are embarrassed, frightened, protecting someone, or unaware that a detail matters medically.
The expression is also part of the show's Sherlock Holmes influence. Like Holmes, House distrusts appearances and searches for evidence beneath the obvious story. The phrase should not be confused with “Everybody dies,” the title of the series finale; the two lines are thematically related but refer to different ideas.