Why is there a white, sticky membrane on the lips upon waking up?

A white, sticky membrane on the lips upon waking is often caused by drooling during sleep; the moisture in saliva evaporates overnight, leaving behind this white film—a benign and common occurrence that typically warrants no concern. Alternatively, it may result from natural shedding of the outer skin layer (epidermis), though it could also be associated with excessive stomach heat (“stomach fire”) in Traditional Chinese Medicine. Patients are advised to maintain a light, bland diet and consume more fresh fruits, which may help alleviate the condition.