What Causes Recurring Throat Pain?

I m a news reader and voice over artist by profession. Recently I m experiencing pain in throat .Whenever it starts paining(probably monthly once ) i go to medical shop and they give me azythromycin tablet.I will feel relieved. But again in few days my throat pain recurs. I ll have difficulty in swallowing, eventually it affects my performance in my profession. I want to know the cause of this problem. (FYI : I never smoke or drink. But i regularly chew orbit or happydent white just as mouth refreshner..may this be a reason)