There are several reasons for the sweetness in the mouth: 1. Consider the relationship with diet, such as the intake of too much sweet food, such as desserts, cream cakes, carbonated drinks, etc., but this sweetness is only temporary, and the symptoms can be relieved after drinking a lot of water or ingesting other foods. 2. The sweetness in the mouth is also a manifestation of damp heat in the spleen and stomach according to the theory of traditional Chinese medicine, because usually like to eat sweet, thick and greasy food, resulting in the transit of the spleen and stomach. The function of the spleen and stomach is obstructed, which will be manifested as sweetness in the mouth, nausea, poor appetite, upper abdominal distension and discomfort. In western medicine, when suffering from digestive system diseases, such as indigestion or chronic gastritis, it will cause sweetness in the mouth and other digestive system symptoms.3. If the patient has diabetes, because the plasma glucose is elevated, it will also cause an increase in the concentration of glucose in the saliva, so there will also be a sticky, sweet feeling in the mouth, so do not be careless with this symptom, and should be further examined.