就诊 (jiù zhěn) literally combines 就 (jiù), meaning 'to approach' or 'to go to', and 诊 (zhěn), meaning 'diagnosis' or 'medical examination'. Together, they form a formal verb meaning 'to seek medical treatment' — specifically, the act of visiting a healthcare provider for evaluation or care. It emphasizes the patient’s action of going to a clinic, hospital, or doctor’s office.

This term is commonly used in official contexts: hospital signage (e.g., 就诊须知 'Instructions for Patients'), medical forms, health insurance documents, and news reports about public health services. It is more formal and clinical than everyday alternatives like 看病 (kàn bìng). While it can be used with or without an object (e.g., 去医院就诊 / 就诊于某医院), it rarely appears in casual speech among friends — there, people prefer simpler expressions like 挂号 (guà hào, 'to register') or 看医生 (kàn yīshēng, 'to see a doctor').