Thick and yellow tongue coating is usually caused by heat in the body, which may be caused by stomach fire, liver fire, heart fire and so on. 1. Exuberant stomach fire: the patient’s diet loves spicy and stimulating food, which damages the spleen and stomach over time, causing exuberant stomach fire, which is characterized by thick yellow tongue coating, accompanied by bad breath, thirst for cold drinks, dry stools and other symptoms. 2. Exuberant liver fire: the patient loves to be angry, and over time, liver depression turns into fire (liver qi is blocked, leading to the production of fire and heat), resulting in a thick yellow tongue coating, symptoms such as irritability, irritability, eye redness, swelling and pain, chest and ribs (chest and rib area) full of stuffiness and other symptoms. 3. Excessive heart fire: Excessive heart fire caused by external fire-heat evil or emotional internal injuries will also lead to symptoms of thick yellow tongue coating, accompanied by insomnia and dreams, heartburn and chest tightness, and red tongue tip. For patients with thick yellow tongue, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor’s diagnosis and treatment with medication, do not take medication to delay the condition, plain diet, avoid spicy and stimulating food.