What medical specialty does Gregory House chiefly practice in House, M.D.?

Gregory House chiefly practices diagnostic medicine in House, M.D. He leads the fictional Department of Diagnostic Medicine at Princeton-Plainsboro Teaching Hospital, where his team investigates rare and unexplained illnesses.

Diagnostic medicine is not presented as a single organ-based specialty in the way cardiology or dermatology is. Instead, House’s work crosses specialties: he combines medical history, laboratory results, imaging, pathology, and consultations to identify a disease that other doctors have not recognized. The series dramatizes this process through differential diagnosis and repeated testing.

House is also described as a specialist in infectious disease and nephrology. Those credentials explain his particular medical expertise, but the department he leads is Diagnostic Medicine. The show’s cases are fictionalized and sometimes compress the time needed for real testing or treatment. Nevertheless, the central idea—that difficult cases may require coordinated reasoning across medical fields—is grounded in the role of diagnostic specialists and consulting physicians.