the white tongue may be caused by various disorders most importantly being Candida fungal infection, Leukoplakic patch, and hypertrphied papillae of unclean tongue. First make a note that whtr, is there, any thing that can be scrapped off from the tongue or not and whtr you are smoker or not? if you are a smoker, then see a dental surgeoun for possible diagnosis of WHITE PATCH (leukoplakia) or Candidiasis infection for which you might require antifungal drugs. Otherwise, use a tooth brush to scrap off the tongue followed by either warm saline solution gargles or of Chlorhexidine mouthwash or Mild Hydrozen Peroxide solution at least twice a day.