noun
medical department; clinical department
Refers to a specialized department within a hospital or clinic, such as internal medicine, surgery, or pediatrics.
この病院には多くの診療科があります。
This hospital has many medical departments.
どの診療科を受診すればいいですか？
Which department should I visit?
Means 'clinic' or 'medical office', a place where medical treatment is provided, whereas 診療科 is the department within a larger medical facility.
Compound of 診療 (shinryō, 'medical examination and treatment') + 科 (ka, 'department, section').