流血 (liú xuè) literally means 'to flow blood' — combining 流 (liú), meaning 'to flow' or 'to stream', and 血 (xuè), meaning 'blood'. As a verb, it describes the physical act of bleeding, whether from a cut, injury, surgery, or medical condition. It is commonly used in everyday health-related contexts, such as first aid, doctor visits, or describing accidents.

The term is neutral in register and appropriate for both spoken and written Chinese. While it can refer to minor bleeding (e.g., a scraped knee), it may also signal more serious situations depending on context and modifiers (e.g., 大量流血 'heavy bleeding'). Unlike some English expressions, 流血 does not carry metaphorical or political connotations unless explicitly extended (e.g., in historical narratives). It is rarely used as a noun on its own; when nominalized, it usually appears as 流血事件 ('bleeding incident') or with measure words like 一次流血 ('an episode of bleeding').