There are many diseases that cause bitter and sticky mouth. Common diseases may include gastroesophageal reflux, cholecystitis, diabetes mellitus and oral diseases. 1. Gastroesophageal reflux: when the peristaltic function of the stomach decreases, the lower esophageal sphincter relaxes, and the esophageal clearance ability decreases, there will be a reflux of food, gastric acid, bile and other substances from the stomach into the oral cavity, and then there will be a bitter and sticky mouth. 2. Cholecystitis: when the gallbladder has gallbladder stones or other causes of inflammatory changes in the gallbladder, it will affect the secretion of bile, and there will also be a bitter and sticky mouth. 3. Oral diseases: chronic inflammation of the submandibular gland in the oral cavity, parotitis, oral gland stones and other diseases, can lead to oral lesions, reduce salivary secretion, resulting in symptoms of dry mouth and sticky mouth. And many older people have decreased tissue and organ function, oral glands atrophy, so that saliva secretion is reduced, but also feel dry mouth and sticky mouth. Symptoms of bitter mouth and sticky mouth, you should go to the regular hospital as soon as possible for examination, after the doctor’s diagnosis and treatment, the cause of the treatment.