The surgery was successful, but he had to endure after-effects like headache and nausea for days.

after-effects 是由 after（在...之后）和 effects（影响、效果）组成的复合名词。effect 来自拉丁语 effectus，意思是"结果、作用"。 after-effects 指"后续影响、后遗症"，特指某个事件或治疗之后持续出现的不良反应或症状。