A Pain
Pain
noun
痛い is "painful." This is the noun version, it is a pain or pain.
The reading is the same as 痛い. No pain here.
俺の伯母さん、クソしてる時に胸にするどい痛みが走って、119に電話したんだ。
My aunt had a sharp pain in her chest while pooping and called 119.