Why Does Your Mouth Feel Dry When You Sleep at Night? 8 Common Reasons to Understand

1. Breathing Through Your Mouth Instead of Your Nose
One of the most frequent culprits for dry mouth during sleep is mouth breathing. When you breathe through your mouth, air flows directly over your tongue and gums, evaporating saliva faster than your body can replace it.

This often happens due to nasal congestion from allergies, a cold, or even structural issues like a deviated septum. Snoring can make it worse, as the open mouth allows even more air movement. Research from sleep experts highlights that nighttime mouth breathing is linked to reduced saliva flow and increased discomfort upon waking.

Simple ways to encourage nose breathing: