Duodenal bulbar ulcer a1 is more serious. Duodenal bulb ulcers are inflammatory reactions and necrotic lesions that occur in the duodenal mucosa under the action of pathogenic factors such as excessive gastric acid secretion and the administration of nonsteroidal anti-inflammatory drugs such as aspirin, and the lesions may reach the muscular layer of the mucosa or deeper. The duodenal bulb is located in the right curvature of the pylorus and is the most common site of duodenal ulcers. Duodenal bulb ulcer a1 stage, i.e., the active stage, refers to the gastroscopic appearance of a localized depression in the duodenum, with white moss on the depression, and congestion and edema of the mucosa and/or submucosa visible around the white moss, suggesting that the duodenal ulcer is in the active stage of the change. In addition, the staging of duodenal bulbous ulcer has H stage (healing stage) and S stage (scarring stage). Duodenal bulbous ulcer a1 stage, it is recommended to consult a doctor in order to clarify the diagnosis, under the guidance of the doctor for targeted treatment.