Stage A1 duodenal ulcers are more severe than stage A2. Duodenal ulcers are categorized into active, healing and scarring stages. The active stage is further divided into stage A1 and stage A2. Stage A2 ulcers generally show normal white moss at the base of the ulcer, clear and without bleeding, and the surrounding inflammatory edema is significantly reduced. Compared with the A2 stage, the mucosal damage in the A1 stage will be more obvious, the white moss on the bottom of the ulcer in the A1 stage is thicker, and the surrounding mucosal congestion and swelling are more obvious, which may be accompanied by obvious bleeding spots. Clinical drugs commonly used in the treatment of duodenal ulcer stage A1 or A2 are gastric acid inhibitors and gastric mucosal protectants. Drugs to reduce gastric acid are commonly used, such as pantoprazole, rabeprazole, omeprazole, etc. Drugs to protect the gastric mucosa, such as aluminum thioglycollate and aluminum phosphate, can also be used for treatment. If the patient suffers from Helicobacter pylori, he or she needs to be treated with a four-pronged approach, i.e., one proton pump inhibitor such as omeprazole + one bismuth such as bismuth pectin + two antibiotics such as amoxicillin and clarithromycin for eradication. Helicobacter pylori is one of the major causes of ulcers. If the patient has duodenal ulcer with complications such as intestinal obstruction and perforation of the bowel, the patient will need to be treated by surgery. If a patient has duodenal ulcer, whether it is stage A1 or A2, the patient should pay attention to it and take treatment in time, so as to avoid more serious damage caused by the continuous development of the disease.