Generally considered to be related to the following factors: First, the digestive system, may be weak spleen and stomach, indigestion, stomach loss and lowering caused by the performance of the stomach descending turbidity, intestinal passages will cause bad breath, white and thick tongue coating, you can take oral Baohe Wan and Yiuyao Wan. If there are teeth marks, you can not exclude the cause of spleen deficiency and dampness, you can take medicine to strengthen the spleen and remove dampness, remove turbidity and phlegm; Second, unclean mouth, plaque, tartar, tartar accumulation is the direct cause of bad breath, mainly manifested as swollen and painful gums, bleeding gums, the need for regular periodontal care and once a year dental cleaning, to develop good oral hygiene habits, as well as the correct method of brushing; Third, chronic rhinitis, sinusitis also can cause bad breath; fourth, with the treatment of drugs, such as antibacterial, radiotherapy, chemotherapy drugs and tonic health products, will make the tongue white and thick, bad breath and other symptoms.