Dry mouth syndrome is usually associated with many viral infections, autoimmune disorders and now, also, COVID-19.
Experiencing a dry mouth basically means that the mouth goes through difficult times of saliva production, which keeps the mouth lubricated, aids digestion, and most importantly, keeps the mouth protected from bad bacteria and other pathogens. A dry mouth can make you feel a feeling of dryness or tightness in your mouth and also make your saliva a little thicker.
Bad breath is also sometimes a common sign of dry mouth. It can also induce difficulty in chewing food, talking and making you experience a feeling of hardness and burning on the roof of your mouth. Right now, you need to check for unusual symptoms like these, at the same time.