Why are our mouths dry in the morning?
Updated February 21, 2017 | Factmonster Staff
![Updated by an Factmonster Editor on February 21, 2017](/themes/ip/images/info-circle.png)
When we sleep, we relax all our muscles, including our jaw muscles. As we relax those muscles our mouths usually fall open, and the air we breathe dries out our mouths. So have that glass of water ready in the morning because no matter what you try to do, your mouth will be dry when you wake up.
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