The pathophysiology of functional dyspepsia is uncertain. It is thought to be a heterogeneous disorder. Various factors have been implicated in the pathophysiology of functional dyspepsia. It has been reported that delayed gastric emptying, impaired proximal gastric accommodation, visceral hypersensitivity and Helicobacter pylori gastritis play a role in development of functional dyspepsia. However, the correlation between these physiological abnormalities and symptomatology of functional dyspepsia is poor. It is still controversial whether these pathophysiological factors are responsible for specific symptoms in functional dyspepsia.