Thick and greasy white coating is mostly due to internal stagnation of dampness and turbidity, or phlegm-drinking (pathological product formed by impaired metabolism of water and fluid), or food accumulation (accumulation of food in the stomach due to indigestion of food). Flat Stomach Powder is used to dry dampness and transport the spleen, and can treat the manifestation of thick and white tongue coating caused by internal stagnation of dampness and turbidity. With the efficacy of drying dampness and transporting the spleen, moving qi and harmonizing the stomach, Ping Gastric San is used for treating dampness stagnation in the spleen and stomach (stagnation of dampness in the spleen and stomach), with symptoms such as fullness in the epigastrium (abdomen), lack of food and drink, blandness and tastelessness in the mouth, nausea and vomiting, belching (belching), swallowing acid (swallowing of acid in the stomach that rushes upward to the oropharynx), heaviness in the limbs, inertia and lethargy, frequent self-liberation, and whitish tongue coating with a thick layer. In this formula, Atractylodes macrocephala enters the middle Jiao to dry dampness and strengthen the spleen; Hou Pu is good at moving qi and removing fullness and can dissolve dampness; Chen Pi regulates qi and harmonizes the stomach, dries dampness and awakens the spleen; Licorice harmonizes the medicines (harmonizes the properties of different traditional Chinese medicines) and strengthens qi and strengthens the spleen; ginger warms and disperses water-dampness and can harmonize the stomach to lower the rebelliousness (harmonize the gastric qi and make the upturned qi to descend); jujube replenishes the spleen and benefits qi, and ginger and jujube together can harmonize the spleen and stomach. This formula should not be used by those with insufficient Yin and fluid or weak spleen and stomach, and pregnant women. When discomfort occurs, one should consult a doctor in time and choose medication under the guidance of physician’s diagnosis, and should not use medication on one’s own in order to avoid delaying the condition.