Waking up with dead skin in your mouth can be from irritation from hot food, vitamin deficiencies or autoimmune diseases.
In most cases the dead skin in your mouth is nothing to worry about and can be resolved with treatment and proper care.
Oral thrush is another cause of dead skin in your mouth.
A tongue that turns black overnight can be a result of dead skin cells accumulating on your tongue.
It can be alarming but it's usually nothing to worry about and will go away by brushing your tongue and keeping your mouth clean and by letting it go away.
A black tongue can also occur due to certain drinks or even medications.
A black hairy tongue is caused by the buildup of dead skin cells on the tiny bumps on the tongue called papillae.
Food, drinks, tobacco, bacteria or yeast, and other substances can get trapped on the papillae and stain them.
Black hairy tongue is a condition of the tongue that gives it a dark, furry look.
Good mouth and tongue cleaning can help get rid of black hairy tongue.
So can stopping things that may lead to the condition, for example, not using tobacco or irritating mouthwashes.
Several antibiotics, including minocycline, doxycycline, erythromycin, linezolid, amoxicillin-clavulanate, metronidazole and piperacillin–tazobactam, have been reported to cause black hairy tongue.