what can cause your tongue to turn a brown color
What You Should Do. Brown or Hairy. Brown tongue or hairy tongue is caused by poor diet and, most often, by poor dental hygiene. The area at the back of the tongue catches food debris, and over time, the debris builds up, causing a brown or brown hairy appearance. Almost all foods can potentially cause brown, hairy tongue. Brush your tongue gently with a soft bristle toothbrush or a tongue scraper.
If your tongue is stained black or dark brown it may be caused by medications and certain foods/drinks. Drinking several cups of coffee or tea per day may stain the tongue; some people who supplement with green drinks containing chlorophyll may notice a very green tongue.