Thick yellow tongue coating is mainly seen in gastrointestinal stagnation, bladder dampness-heat, phlegm-dampness, and stagnation of evil qi. It is closely related to the following factors. 1. Improper diet: overeating sweet and fatty, spicy and stimulating food, excessive alcohol consumption. 2. Drugs: the abuse of tonic drugs can also cause the body of dampness and heat, resulting in a thick yellow tongue. 3. Lifestyle habits: sedentary, holding urine, unclean hygiene habits. 4. Disease factors: Spleen and stomach dysfunction, i.e., the spleen and stomach is weak, unable to properly digest and absorb food. Common causes include gastrointestinal stagnation, dampness and heat in the bladder, phlegm and dampness, and stagnation of evil qi. 5. Environmental factors: high temperature in summer, the human body due to sweating will evaporate a lot of water, dampness and heat easily stagnate in the body. Tongue thick yellow may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.