Slight thickening of the mucosa of the lower esophagus may be caused by reflux esophagitis, esophageal cancer, etc. After clarifying the cause, medication or endoscopic treatment can be taken. 1. Reflux esophagitis: food and stomach acid in the stomach flows back into the esophagus, which damages the mucous membrane of the esophagus and produces inflammatory reaction and edema. When the esophagus is edematous, the mucosa of the lower esophagus can be slightly thickened. Drug treatment can be used, such as proton pump inhibitors like omeprazole, gastric mucosa protectors like aluminum thioglycollate, and gastric stimulants like domperidone. 2. Esophageal cancer: esophageal epithelial cell carcinoma can thicken the esophageal wall, and the mucosa of the lower esophagus can be slightly thickened. Treatment can be endoscopic, such as endoscopic mucosal resection, endoscopic submucosal dissection. Surgical treatment or radiotherapy or chemotherapy may be used if necessary. Slight thickening of the mucosa of the lower esophagus may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.