What specialty does Gregory House head at Princeton-Plainsboro in House M.D.?

Gregory House heads the Department of Diagnostic Medicine at Princeton-Plainsboro Teaching Hospital in House M.D. The department investigates difficult cases that have resisted ordinary diagnosis.

The premise gives House and his fellows access to patients with rare, unusual, or conflicting symptoms. Rather than focusing on one organ system, diagnostic medicine draws on multiple specialties and uses a process of forming, testing, and eliminating hypotheses. The show's famous team discussions dramatize that process for viewers.

House is also described as having expertise in infectious disease and nephrology, which can cause confusion about the department he runs. Those are his medical specialties, but the department's name is Diagnostic Medicine. The show therefore distinguishes House's personal training from the broader hospital unit responsible for solving complex cases.