Which fictional department does Gregory House lead in House M.D.?

Gregory House leads the fictional Department of Diagnostic Medicine in House M.D. at Princeton-Plainsboro Teaching Hospital.

The department handles patients whose symptoms do not fit an obvious diagnosis. House assembles a small team of doctors who propose possibilities, order tests, and revise their theories as new evidence appears. This structure gives the series its signature medical-mystery format.

Diagnostic medicine is a real area of medical practice, although the show's department and House's unusually broad authority are fictionalized for drama. In real hospitals, difficult cases may involve consultation among multiple specialties rather than one diagnostician directing every step.

The department is sometimes mistaken for infectious diseases because many episodes involve infections. House's team, however, is not limited to one disease category. It investigates rare, complex, and unexplained conditions across specialties.