There are four most common complications of peptic ulcer. First, upper gastrointestinal bleeding, which is also the most common complication of peptic ulcer, especially bleeding from duodenal bulb ulcer is most common, and the clinical manifestations are mainly vomiting blood and black stool. If the bleeding volume exceeds 400 ml, the patient may have systemic symptoms, such as weakness, dizziness, chest tightness, and panic. If the bleeding volume is very large and exceeds 1000ml in a short period of time, symptoms of peripheral circulatory failure and shock can occur. Second, peptic perforation, when the ulcer is very deep and penetrates the plasma membrane layer, perforation can occur, and the clinical manifestations are mainly sudden and severe abdominal pain, abdominal pain refusing to press, with the manifestation of peritonitis. Pyloric obstruction, the vast majority of pyloric obstruction is caused by ulcers in the duodenal bulb, and a small proportion is caused by ulcers in the pyloric duct and the pre-pyloric area, the main clinical symptoms are epigastric distension and discomfort, obvious after meals, accompanied by vomiting, and the symptoms are alleviated after vomiting. Fourth, cancer, a small proportion of gastric ulcer patients can appear cancer of the stomach, but generally cancer of the duodenal bulb rarely occurs.