A white film appears in my mouth when I wake up.

A white film you notice on waking is usually a shallow layer of the lining of the mouth that has peeled away. Common causes are 1) irritation from the surfactant (SLS) in toothpaste, 2) a dry mouth during sleep, often from sleeping with your mouth open, and 3) unconsciously biting the inside of your cheek. It often improves if you switch to a low-irritation (SLS-free) toothpaste and drink enough water before bed. However, if the white film does not wipe away and stays fixed in place, or pain or stinging lasts more than 2 weeks, an oral mucosal condition needs to be ruled out, so please come in.