Atrophic gastritis C1 C2 C3 is the extent or size of gastric atrophy. Atrophic gastritis can be categorized into six types based on the extent of distribution which are C1, C2, C3, O1, O2 and O3.The categorization is based on the extent or size of the atrophy. The extent of atrophic gastritis from the antrum, antrum, lesser curvature of the gastric body to the cardia is C1, C2 and C3 respectively. C1 refers to chronic atrophic gastritis in which the lesion is located in the gastric sinus and does not extend beyond the gastric angle of the lesser curvature of the gastric body.C2 refers to atrophy of the mucosa of the gastric angle, with the lesion reaching the middle and lower part of the lesser curvature of the gastric body.C3 refers to the atrophic gastric mucosal lesion reaching the upper part of the lesser curvature of the gastric body, close to the cardia. It is recommended that patients with atrophic gastritis should consult a doctor in time and use reasonable drugs under the guidance of the doctor. Usually should quit smoking and avoid alcohol, avoid the use of drugs that damage the gastric mucosa.