This document discusses peptic ulcer disease (PUD). PUD is characterized by damage to the gastrointestinal tract caused by gastric acid and pepsin. Common symptoms include abdominal pain, dyspepsia, nausea, and vomiting. Diagnosis involves endoscopy, imaging, and tests for Helicobacter pylori infection. Treatment consists of proton pump inhibitors, antibiotics, cytoprotective agents, and diet modifications. Complications can include perforation, penetration, hemorrhage, and obstruction.