Gastroesophageal reflux disease (GERD) is a clinical syndrome characterized by heartburn and acid reflux caused by the reflux of gastric and duodenal contents into the esophagus. In the past, it was thought that NERD was a milder form of RE, and that GERD progressed from NERD to RE and then to Barrett’s esophagus (BE) and esophageal adenocarcinoma. However, recent studies tend to consider NERD, RE and BE as three separate diseases, each with its own separate pathogenesis and complications, almost independent of each other. Although RE is a more severe lesion than NERD, the response to treatment is better than that of NERD. There is no evidence to support the progression of NERD to RE, nor is it possible to prove that BE evolves from RE or NERD. The incidence of GERD is very high in western countries, with a population prevalence of 10%-30%. The results of epidemiological surveys in Beijing, Shanghai, Guangzhou and Xi’an show that the prevalence of reflux symptoms such as heartburn and acid reflux is 8.9% and 16.9%, and the prevalence of confirmed GERD is 3.87% and 5.77%, while that of reflux esophagitis is 1.92% and 2.40%.