Mouth and tongue means that the mouth is not dry, saliva secretion is more, the mouth is moist and sweet. Salivary glands in the mouth have the function of secretion of saliva, normal people can generally secrete 1 ~ 1.5L of saliva every day, saliva in the mouth contains salivary amylase, mucin, lysozyme, etc., which can make people feel that there is a sweet flavor in saliva. Mouth and tongue is due to the salivary glands secretion of saliva is more vigorous, bad dietary habits can lead to oral dryness less Jin, such as eating too much stimulating spicy food, long time to stay up all night, smoking and drinking, insufficient intake of water will lead to the mouth and tongue fluid lack. Therefore, usually develop a good dietary habits, drink more boiled water, eat a light diet.