Duodenal ulcers can cause symptoms such as upper abdominal pain, belching, acid reflux, nausea, vomiting, heartburn, poor appetite, and indigestion. The characteristic of upper abdominal pain in duodenal ulcers typically lessens after eating and worsens when hungry. A gastroscope can reveal defects in the duodenal mucosa, confirming a diagnosis of duodenal ulcer. About 90%-100% of patients with duodenal ulcers are infected with Helicobacter pylori, therefore, a Carbon-14 breath test is recommended to determine the presence of Helicobacter pylori infection. If the infection is positive, a 14-day eradication treatment for Helicobacter pylori is required, involving a proton pump inhibitor, two types of antibiotics, and a bismuth agent. Additionally, treatment for duodenal ulcers includes acid suppression, gastric protection, enhancing gastric motility, and protecting the gastric mucosa. The treatment typically lasts about six weeks.