if you are run down or poorly it could be thrush which needs treating by your doctor. i agree... drink water, sparking might help to clean your tongue. also use a soft toothbrush to brush your tongue everytime you brush your teeth. change your toothbrush regulary. hope this helps
Sometimes a white color or coating on the top of the tongue may be due to not getting enough fluid. Maybe you should try and drink 8oz of water a day. You should also seek a healthcare provider to be on the safe side.