Dyspepsia (DP) is pain or discomfort in the upper abdomen. It may be uninvestigated dyspepsia or functional dyspepsia (FD) which is diagnosed after diagnostic tests such as upper endoscopy and occasionally upper abdominal ultrasound find no organic changes that explain the condition. Despite the wide dissemination of the classifications of dyspepsia, functional dyspepsia and postprandial dyspepsia, recent findings controvert these classifications. This article discusses the approach to patients with dyspepsia and the pathophysiology and drug treatment of functional dyspepsia.