Chronic gastritis is the inflammatory lesion of the gastric mucosa caused by a variety of factors. Its clinical manifestations include epigastric discomfort or pain, anorexia, nausea, vomiting, belching, diarrhea, etc. Chronic gastritis has a high incidence with more than 20 % of the adults affected and the incidence increases with age. According to the morphological change under the gastrofiberscope, this disease is classified into chronic superficial gastritis and chronic atrophic gastritis. The superficial layer of the gastric membrane is mainly affected in chronic superficial gastritis while chronic atrophic gastritis is characterized by the atrophy of the connatural glands of the gastric membrane, often accompanied with intestinal metaplasia and inflammatory reaction.

Chronic gastritis belongs to the categories of "wei tong" (gastric pain), "pi man" (feeling of fullness), "ou tu" (vomiting), "cao za" (gastric discomfort) and "tun suan" (acid regurgitation) in TCM. It is believed that chronic gastritis is due to improper diet, irregular intake of food, or overeating of cold and raw food, irritating food, cigarette smoking and indulge in alcohol which damdage the spleen and stomach, causing undescending of stomach qi and qi stagnation; it may also be caused by emotional disturbance which results in stagnant liver qi attacking the stomach, or stagnant liver qi turning into fire which damages stomach yin; or long-term disorders causing qi and blood stagnation in the stomach channel.