4 More Causes You Didn’t Expect

5. Diabetes – High blood sugar makes kidneys work harder, draining fluids and causing a dry mouth at night.

6. Bile Reflux – Digestive issues like bile reflux can lead to nighttime dryness; supporting liver health can help.

7. Fever – Your body loses extra fluids during a fever, leaving your mouth dry and tongue irritated.

8. Hyperthyroidism – An overactive thyroid increases water needs, so even asleep, your mouth may feel unusually dry.

If dry mouth persists, it’s best to consult a doctor—it could be a sign of an underlying health problem. Small changes in diet, hydration, and dental care can make a big difference.