Hello, thick tongue coating is caused by damp-heat of spleen and stomach or gastrointestinal stagnation, which is seen in infection, fever or digestive dysfunction, and is often accompanied by thirst and irritability of the tongue. To avoid slow intestinal peristalsis at night and increase intestinal burden. Eat less high-fat and high-protein food, eat more fruits and vegetables, try to use less fried cooking methods and drink something cooler than that.