What is Gregory House’s primary medical specialty in House M.D.?

Gregory House’s primary medical specialty in House M.D. is diagnostic medicine. He heads the hospital’s Department of Diagnostic Medicine and tackles cases that other physicians have been unable to solve.

House’s diagnostic work is portrayed as a process of generating, testing, and eliminating hypotheses. His team reviews symptoms, medical histories, laboratory results, and imaging before recommending treatment. The drama often emphasizes that a rare diagnosis may be hidden by an apparently ordinary symptom or by misleading test results.

House is also described as a specialist in infectious disease and nephrology, which reflects his medical training and broad clinical knowledge. Those specialties are related to his expertise, but they are not the name of the department he leads. The show’s central premise depends on diagnostic medicine as a distinct hospital function, making that the most precise answer.