The causes of severe dry mouth without high blood sugar are: 1, the formation of stones or foreign bodies in the ducts of salivary glands such as the parotid and submandibular glands, the mucus secreted cannot be discharged into the mouth, the mucous membrane lacks flushing and becomes dry. 2, the formation of mucous cysts in the submucous glands of the lips, the lubricating effect on the mucous membrane is weakened, and dry mouth symptoms can occur. 3, the body’s immunity is low, endocrine disorders, salivary gland structure destruction, volume Atrophy occurs, liquid secretion decreases significantly, and chapping and burning pain occurs in the lips, cheeks, tongue and other parts.