I recently went to the Dentist, who mentioned that I had dry mouth. I'd never really noticed it and didn't respond due to instruments and fingers in my mouth at the time. Shortly after said visit, I began waking up in the middle of the night and reaching for a sip of water, now on a regular basis. It's been a few weeks now and I also notice or feel like the inside of my mouth is swelling up. I used to be able to run my tongue below my lower teeth to check for anything there, and now I can't do it any more. Anyone have a clue?

Drink more, as it's a sign of dehydration.

Do you take any medications?