“失去知觉”常见的英文表达是 “lose consciousness” ，也可用 “become unconscious” 。
lose consciousness：强调从有知觉到失去知觉这一动作过程。例如：He hit his head on the ground and lost consciousness.（他的头撞到了地上，失去了知觉。）
become unconscious：侧重于描述状态的转变，即从有意识状态转变为无意识状态。例如：The patient became unconscious after the operation.（手术之后，病人失去了知觉 。 ）