I woke up with very dry mouth, blood covering my tongue, roof of mouth, teeth, lips and little bit blood stains on my pillow. what could it be?

More info needed: Did you have a dental procedure recently? Did you sustain any trauma to your jaw or eating really hard foods? Do you have any health issues like a bleeding disorder or are taking a blood thinner. Do you have sleep apnea? Sleep apnea patients snore very loudly and this can lead to a dry mouth and a traumatized palate.

Periodontal desease: One possibility is severe periodontal disease. This affects the gums and bone surrounding your teeth. The gums become very inflamed and will bleed very easily. There other possibilities which should be ruled out by a professional.

Need an evaluation: Bleeding or blood in the mouth not normal and should be taken seriously. A good place to start is with your dentist and physician. You may have periodontal disease and your body may be having an exaggerated response to the higher levels of bacteria below the gumline. Without immediate aggressive intervention, tooth loss is possible. See your physician to rule out systemic illness/infection.