Dyspepsia affects up to 40 percent of adults each year and is often diagnosed as functional (nonulcer) dyspepsia. The defining symptoms are postprandial fullness, early satiation, or epigastric pain or burning in the absence of causative structural disease. These symptoms may coexist with symptoms of functional gastrointestinal disorders, such as gastroesophageal reflux and irritable bowel syndrome, as well as anxiety and depression. The history and physical examination can help identify other possible causes of the symptoms. Warning signs of serious disease, such as cancer, are unintended weight loss, progressive dysphagia, persistent vomiting, evidence of gastrointestinal bleeding, and a family history of cancer. In these cases, more extensive laboratory investigation, imaging, and endoscopy should be considered as clinically indicated. During the initial evaluation, a test-and-treat strategy to identify and eradicate Helicobacter pylori infection is more effective than empiric treatment and more cost-effective than initial endoscopy. Eradication of H. pylori helps one out of 15 patients with functional dyspepsia diagnosed by endoscopy, but may not be cost-effective. Treatment options that may be beneficial for functional dyspepsia include histamine H2 blockers, proton pump inhibitors, and prokinetic agents. Although psychotropic medications and psychological interventions have no proven benefit in patients with functional dyspepsia, they are appropriate for treating common psychiatric comorbidities.