3.Dehydration
If you don’t drink enough water, your body will become dehydrated. You lose water when you sleep as you breathe, and as your body functions. When you sleep, all of your bodily processes need water. If your body doesn’t have enough water, your mouth will be dry. It’s important to drink more water regularly.
4.Oral diseases
If you have periodontitis, gingivitis, or gum disease, there will be a lot of bacteria and viruses in your mouth. If your mouth is not sufficiently clean, the bacteria and viruses will continue to reproduce and grow. This can lead to inflammation and a dry mouth at night.
5.Diabetes
Many diabetic patients find they have a dry mouth and bitter taste in their mouths at night. This happens because the sugar in their blood rises and keeps building up. Then the kidneys and liver metabolize the sugar, which causes faster water loss. This makes the mouth dry when you’re sleeping.
