Duodenal ulcer is related to genetic predisposition, Helicobacter pylori infection, abnormal gastric acid secretion, weakened defense mechanism of duodenal mucosa, etc., and the cause should be identified by timely consultation. Duodenal ulcer is one of the common and frequent diseases in our population, and is a common type of peptic ulcer. It is a common type of peptic ulcer. It occurs in winter and spring when the climate is changing. The incidence rate of men is significantly higher than that of women. It is closely related to abnormal gastric acid secretion, H. pylori infection, non-steroidal anti-inflammatory drugs (NSAIDs), irregular life and diet, work and external stress, smoking, drinking, and mental and psychological factors. Duodenal ulcers mostly occur in the duodenal bulb (95%), with a predominance of the anterior wall, followed by the posterior, inferior, and superior walls. 1. Helicobacter pylori infection: Helicobacter pylori infection is an important cause of peptic ulcer recurrence, . 2. Abnormal gastric acid secretion: a large number of clinical trials and studies have proved that the pathological elevation of gastric acid is one of the important factors in the development of ulcer. Excessive acidity of gastric juice activates pepsinogen, which causes the duodenal mucosa to digest itself and may be an important cause of ulcer formation. 3. Duodenal mucosal defense mechanism is weakened: some patients with duodenal ulcer disease, gastric emptying faster than normal. Liquid emptying is too fast so that the duodenal bulb is in contact with gastric acid for a longer period of time, and the mucosa is easy to be damaged. 4. Genetic factors play a more important role in the susceptibility to this disease, with the family incidence of patients being 2.6 times higher than that of the general population. Duodenal ulcer may also be caused by other factors, it is recommended that the patient timely consultation, by the doctor to clarify the cause of the disease, give targeted treatment.