What was Gregory House's medical specialty before leading diagnostics in House M.D.?

Gregory House's medical specialties are infectious disease and nephrology in House M.D. Those fields help explain why he is particularly skilled at recognizing systemic illnesses, unusual infections, and kidney-related disorders.

Infectious disease concerns illnesses caused by bacteria, viruses, fungi, parasites, and other infectious agents. Nephrology focuses on the kidneys, including their function, diseases, and effects on the rest of the body. House's diagnostic work often draws on both areas, although the series presents him as a broader diagnostician rather than as a conventional single-specialty consultant.

Viewers sometimes identify House only as a diagnostician or assume that his department is nephrology. Diagnostic Medicine is the hospital department he leads; infectious disease and nephrology describe his clinical specialties and training.

House's medical knowledge is paired with an analytical style modeled partly on detective fiction. The show uses that combination to make rare diagnoses central to its plot, while the character's chronic pain and dependence on Vicodin create a separate ongoing storyline.