Dry mouth and sour mouth may be a normal physiological phenomenon, or it may be caused by chronic gastritis, diabetes and so on. You should go to the hospital to clarify the specific cause of the disease. 1. Physiological phenomenon: Prolonged poor dietary habits, such as eating spicy and stimulating foods like chili peppers and onions, or eating overly sweet foods like chocolate, may lead to dry mouth and sour mouth. It can be treated by improving diet, etc. 2. Pathologic phenomena: (1) Chronic gastritis: Chronic gastritis refers to chronic inflammatory lesions of the gastric mucosa caused by a variety of etiologic factors. Gastritis can lead to excessive secretion of gastric acid, which results in the phenomenon of dry mouth and sour taste in the mouth. It can be treated by drugs such as rabeprazole. (2) Diabetes mellitus: Diabetes mellitus is a group of disorders of protein, carbohydrate, and fat metabolism caused by absolute or relative insufficiency of insulin secretion and impaired utilization of insulin. Diabetic patients will be due to elevated blood glucose, osmotic diuresis in the body, the symptoms of dry mouth and sour mouth, can be treated by controlling blood glucose. It is recommended that patients with symptoms of dry mouth and sour mouth should go to the hospital in a timely manner, to clarify the cause of the disease, under the guidance of the doctor for treatment.