Diabetes mellitus patients in the blood sugar control stable after the appearance of the mouth is always dry symptoms to consider may be diet, environment, drugs and other factors, or uremia, dry syndrome and other disease factors. 1. Dietary and environmental factors: low water intake, like to eat some spicy and stimulating, fatty foods and other dietary factors may cause dry mouth; long term in a high temperature state leads to skin cooling function decline, body temperature rises, dehydration symptoms can cause dry mouth. 2. Disease factors: uremia can cause antidiuretic hormone regulation, transportation, release function decline, kidney reabsorption capacity decline, ultimately causing dry mouth; dry syndrome can cause salivary glands and lacrimal glands to reduce secretion, resulting in dry mouth symptoms. 3. Drug factors: diabetic patients with hypertension may need to use diuretics for antihypertensive treatment, and diuretics may cause dry mouth adverse reactions. Diabetic patients with dry mouth are advised to go to the hospital if necessary, and ask the doctor to make a judgment, and should not make a blind judgment on their own.