Duodenal compression syndrome, i.e., superior mesenteric artery syndrome, is usually not due to gastritis, but may be due to congenital anomalies, tumors, adhesions after gallbladder and stomach surgery, and excessive weight loss. 1. Congenital anomalies: the presence of congenital peritoneal fascicle blocking the duodenum by compression and pulling, congenital stenosis or occlusion of the distal part of the duodenum, and compression of the descending part of the duodenum by the annular pancreas may lead to superior mesenteric artery syndrome. 2. Tumor: when suffering from malignant tumor, renal tumor, pancreatic cancer, lymphoma, metastatic cancer of duodenum and other tumors, it may compress the duodenum, and then lead to superior mesenteric artery syndrome. 3. Adhesion after gallbladder and stomach surgery: Adhesion after surgery may pull the duodenum, thus increasing the chance of suffering from superior mesenteric artery syndrome. 4. Excessive weight loss: Excessive weight loss may cause rapid weight loss. When the body is excessively thin, the abdominal wall is loose and the abdominal muscles are weak, which may lead to the relaxation of the muscles and ligaments that suspend and fix the stomach and duodenum, and then trigger the superior mesenteric artery syndrome. If you want to find out the cause of superior mesenteric artery syndrome, it is recommended to go to the hospital in time and determine the cause of the disease by combining the results of relevant tests after the doctor’s interview.