The first and second of the three strictures of the esophagus have no specific name, and the third stricture is called the cardia. The first stricture is located at the entrance to the esophagus, which is the location of the esophageal pharynx. The second stricture is at the bifurcation of the trachea, at the position of the arch of the aorta, and also at the angle of the sternum, a position that is prone to esophageal cancer. The third stricture is called cardia, which is mainly at the junction of stomach and esophagus. This location is prone to carditis, cardia mucosal tear or esophageal cardia loss, and in some cases, esophageal cancer may also occur. Most of the three narrowings of the esophagus have great clinical significance. The clinical significance of the entrance of the esophagus is that it is prone to food stagnation, the second narrowing is prone to esophageal cancer, and the third narrowing is prone to bleeding.