Peptic ulcers include gastric ulcers, duodenal bulb ulcers, and gastro-duodenal composite ulcers. The common characteristic of peptic ulcers is upper abdominal pain, which tends to be recurrent, periodic, and regular. For duodenal bulb ulcers, the pain is primarily located above and to the right of the navel, mainly manifesting as hunger pain in the upper abdomen, which can be alleviated after eating, accompanied by nocturnal pain. Sometimes, bulb ulcers can cause back pain. Gastric ulcers are mainly located above and to the left of the navel, primarily characterized by postprandial pain.