Chronic atrophic gastritis C2 means that the atrophy is of closed atrophy and the atrophy reaches beyond the angle of the stomach, and with erosion means that the atrophy of the gastric mucosa is accompanied by erosion. Chronic atrophic gastritis can be categorized into two types according to the type of atrophy, i.e., closed atrophy is indicated by the letter C and open atrophy is indicated by the letter O, while the number following the letter indicates the part of the atrophy reached. For example, the number 1 indicates that it is still confined to the sinus, the number 2 indicates that the atrophy exceeds the angle of the stomach, and the number 3 indicates that the atrophy has approached the cardia. Therefore, C2 indicates closed atrophy that extends beyond the angle of the stomach. The presence of erosion indicates that the patient’s gastric mucosa has both atrophy and erosion. If the examination found that chronic atrophic gastritis C2 with erosion, it is recommended to timely consult a professional doctor for diagnosis and treatment.