Noncardiac chest pain (NCCP) is a common clinical problem worldwide. In Hong Kong, it has been estimated that about 20% of patients with chest pain are misdiagnosed to have coronary heart disease. Despite its benign nature, this condition causes anxiety, impairs quality of life and consumes a substantial amount of healthcare resources. While acid reflux and motility disorder in the esophagus are often attributed as the cause of NCCP, visceral hyperalgesia of esophagus is now recognized to play a central role in the pathogenesis of this condition. This research project aims to evaluate the role of visceral hyperalgesia in Chinese patients with NCCP. NCCP patients will be evaluated for the prevalence of gastroesophageal reflux disease and esophageal motility disorder by endoscopy, manometry and pH study. The visceral sensory and pain thresholds of these patients will be compared with asymptomatic controls.