What are the names of House's two medical specialties in House M.D.?

House's two medical specialties in House M.D. are nephrology and infectious disease.

Nephrology is the medical specialty focused on the kidneys and related disorders. Infectious disease concerns illnesses caused by pathogens such as bacteria, viruses, fungi, and parasites. House's training in both fields gives him a broad base for approaching unusual cases.

The specialties are distinct from his hospital role. House heads Diagnostic Medicine, the department responsible for solving especially difficult cases. His formal qualifications help explain why he can move between organ systems and consider infections, kidney problems, autoimmune conditions, and other causes in the same investigation.

Viewers sometimes answer “diagnostic medicine,” because that is House's department and the job most closely associated with him. The more specific answer about his medical specialties is nephrology and infectious disease. The series uses this combination to support House's reputation as a physician who connects clues across disciplines.