The causes of astringency of the patient’s tongue depends on whether it is combined with other symptoms, as follows: 1, hematologic disorders: the patient’s tongue is numb, astringent, purple, we should pay attention to whether there is a lack of qi and blood, insufficient blood circulation, blood viscosity is too high, insufficient blood supply, etc., pay attention to the blood pressure, blood sugar, blood routine, blood lipids aspects of the examination, whether there are related to the abnormality of the 2, digestive disorders: If the tongue astringency combined with the symptoms of bitter mouth, we should pay attention to whether there is a poor digestive function, biliary tract disease. The symptoms of bitter mouth, we should pay attention to whether there is poor digestive function, biliary tract disease, etc. 3, other reasons: if the tongue astringent combined with the appearance of taste buds abnormalities, including dry mouth, tongue thickening, we should pay attention to whether there is an abnormal infection of the oral cavity, drinking too little water, taking some abnormal drugs caused by. Causes of the patient’s tongue astringency for many reasons, the key to be integrated for consideration, in order to know the specific factors.