The next most important cause of unexplained chest pain would be gastro-esophageal reflux disease (GERD). GERD and its complications of Barrett's oesophagus and oesophageal adenocarcinoma have increased markedly in recent decades, not just in the developed countries but also in Asia. Although relatively less common among populations in Malaysia, there are data to suggest an increasing prevalence of reflux disease largely a result of obesity and increased intra-abdominal pressure.