Clinically, duodenal ulcer is more common than gastric ulcer, and the latest statistical data is 1.56: 1. Gastric ulcer is generally larger than duodenal ulcer. Gastric ulcer and duodenal ulcer are often accompanied by chronic gastritis, and the incidence of gastric ulcer is high.

The most common symptom of gastric ulcer is abdominal pain or abdominal discomfort, which is usually located under the xiphoid process of the upper abdomen and sometimes on the left side. Pain lacks typical rhythm, and abdominal pain occurs in the early after meals.

Abdominal pain of duodenal ulcer is mostly rhythmic, periodic and long-term. Localized abdominal pain often occurs on an empty stomach, especially at 10- 1 p.m., 3-4 p.m. and10-p.m.. Most of the painful parts are on the right side under the xiphoid process. Periodic attack and remission are the manifestations of duodenal ulcer protrusion. The duration of each attack is different, about half is 2-4 weeks, and the rest is only a few days, and the length can reach 8- 10 weeks. The remission period between two episodes is also different, some are 1-3 months, some are shorter, some are longer, and occasionally the remission period after one episode is as long as more than ten years. In remission, patients can eat at will without pain. In many cases, this periodic attack is seasonal, usually in spring and autumn, but it is relieved in summer and winter, which is related to climate change. In addition, gastric ulcer can be partially cancerated, while the canceration rate of duodenal ulcer is extremely low.