What medical specialty does Gregory House lead in House M.D.?

Gregory House leads the Diagnostic Medicine department in House M.D.

The department handles difficult cases that other hospital specialists have been unable to explain. House and his rotating team use patient histories, tests, differential diagnoses, and sometimes risky procedures to identify the underlying disease. This structure supplies the central medical mystery in most episodes.

Diagnostic medicine is distinct from a conventional organ-based specialty such as cardiology or neurosurgery. A diagnostician may draw on knowledge from many fields because unexplained illness can involve several body systems at once. The show dramatizes this broad approach through House’s team discussions and diagnostic hypotheses.

House is also described as having expertise in infectious disease and nephrology, which can cause confusion about the department he heads. Those are his professional specialties, but the hospital department at the heart of the series is Diagnostic Medicine.