Why do I have a dry mouth even after I've consumed a lot of water?

Xerostomia. Chronic dry mouth is called xerostomia. It can have many causes including pathology in the oral cavity or prescription drugs. See your dentist to determine the cause of your xerostomia. Chronic dry mouth can lead to tooth decay, so impeccable oral hygiene is very important for you. Cut down on sweets and do not suck on hard candy to make your mouth moist. Sugar free gum is ok.
Diabetes ? Are you diabetic? Or do you take a lot of medication? Some medical conditions such as diabetes or some diseases such as sjögren's syndrom, or medications can cause a dry mouth. You should check your blood sugar, limit you sugar intake and see your doctor to get a physical.
Different situations. Dry mouth can be observed in patients taking certain medications, and also patients that have received radiation therapy on head and neck among other situations or affections in the salivary glands.. The best way to determine if there is a real reduction in the production of saliva is to do a proper measurement.