Dilatation of the esophagus can be categorized as primary or secondary. Dilatation that occurs above the narrowed part of the esophagus belongs to secondary dilatation, which can be categorized into extensive dilatation and limited dilatation. Secondary dilatation is less common, and is mostly secondary to esophageal cancer and gastric cancer. Esophageal dilatation may be caused by extensive dilatation or limited dilatation. 1. Widespread dilatation: the cause is unknown and there is no specific preventive measure. Its clinical manifestation is the dilatation of the whole esophagus, which is caused by the dysfunction of the nerves and muscles of the esophagus, so this type can also be called megaesophagus. 2. Restricted dilatation: This is the sudden enlargement of a section of the esophagus, which is also known as esophageal diverticulum. Diverticula are formed because the smooth muscle of the esophageal wall is not well developed congenitally, and the mucosa located on its surface is very weak and easily protrudes out of the lumen of the esophagus. Diverticula often occur in the part of the esophagus where the pharynx meets the esophagus, and rarely in the lower esophagus. 3. Secondary esophageal dilatation: it is rare, mostly secondary to esophageal cancer and stomach cancer. Bad dietary habits in daily life, such as not eating moldy food, eating less or not eating sauerkraut, reducing nitrite content in drinking water. It is recommended that you should consult a doctor in time to clarify the cause of the disease and conduct appropriate tests if necessary.