<s>[INST] I have a dry tongue (at the rear). I drink alot of water (approx 4 - 6 litres) which I in my opinion rules out dehidration.  In the past year I have lost 9 1/2 stone on the LighterLife plan.  I have been maintaining for the last four months & eating proper foods.  The dry tongue started whilst I was on the total plan ( packs only) but has continued now I am back on normal foods! [/INST] Hi,Thanks for asking the query,Dry tongue occurs due to use of certain medications like hypertension, diuretics, urinary incontinence, smoking, chewing tobacco, nutritional deficiencies, dehydrations.As you have mentioned you are drinking plenty of water, i would suggest you to use sugar free chewing gums.Visit to the Dentist and get a checkup once.Breathing through your nose and not from your mouth.Take multivitamin suplements.Take lukewarm saline gargles and antiseptic mouthwash .Use fluoridated toothbrush and brush your teeth twice daily.Avoid smoking habit for some days if present.Hope this helps out,Regards.. </s>