A shallow depressed lesion on the side of the lesser curvature of the gastric sinus, covered with thin white moss, about 0.5*0.5cm in size, may be superficial gastritis, gastric ulcer, gastric cancer, etc., and should be promptly consulted to find out the cause. 1. Superficial gastritis: Helicobacter pylori infection is the main cause of gastritis, and other causes include smoking, reflux, poor diet, etc. When examining, it can be found that there is a depressed lesion on the side of the lesser curvature of the gastric sinus, covered with thin white moss; the patient may suffer from loss of appetite, belching (burping), nausea and other symptoms. 2. Gastric ulcer: Among the causes of ulcer, Helicobacter pylori infection and non-steroidal anti-inflammatory drugs can cause ulcer, which is accompanied by dyspepsia, loss of appetite and unexplained weight loss. Examination may reveal a shallow depressed lesion on the side of the lesser curvature of the gastric sinus, covered with thin white moss. 3. Gastric cancer: It is caused by a combination of factors, the most common causes include Helicobacter pylori infection, precancerous lesions, genetic factors, environmental factors and so on. Early gastric cancer patients mostly have no obvious symptoms, but a few of them have fullness and bloating, dyspepsia, etc. Gastroscopy can find that the small curvature of the gastric sinus is covered with thin white moss in a concave lesion. Gastroscopy can find a shallow depressed lesion at the lesser curvature of gastric sinus, covered with thin white moss, about 0.5*0.5cm in size, there may be other reasons, so one should consult a doctor in time, ask him to clarify the specific reasons, and then carry out the corresponding treatment if necessary.