流血(liú xuè) - to bleed, to shed blood in Mandarin

流血 (liú xuè) is to bleed. Grammatically it is a verb plus its own object, flow-blood, which is why the thing that bleeds is the subject and nothing else needs to follow: 他流血了 is he is bleeding, full stop. For a particular body part, name it as the subject, as in 鼻子流血, his nose is bleeding.

It carries a second, heavier sense of shedding blood in conflict, and 流血事件 is a violent incident in news language. The neutral medical alternative is 出血, which is what a doctor writes on a chart.

Two traps. First, because the object is built in, you cannot say 流血我的手; the injured part becomes the subject or takes 的. Second, 血 has two readings: the formal xuè used here and in 流血, and the colloquial xiě heard in everyday sentences such as 出血了. Both are correct, and our audio uses xuè.