Always feel dry mouth reasons are: 1, the body autoimmune disease, hormone levels are not stable, induced oral dryness syndrome when the salivary glands are damaged, the secretion is greatly reduced, resulting in the lack of mucus lubrication of the oral cavity, lips, cheeks, tongue mucosa, cracked and dry, resulting in a burning sensation; 2, the sublingual gland, submandibular gland, parotid gland and other conduits within the formation of foreign bodies such as stones, resulting in obstruction, the glands can not be discharged to the oral cavity of the secretion of fluids, resulting in the oral mucosa feel dry; 3, can not replenish the water in a timely manner, the intake of fruits is low, you will often feel dry.