Superior mesenteric artery embolism is a disease caused by vascular obstruction due to emboli entering the superior mesenteric artery, manifested by abdominal pain, abdominal distension, nausea, vomiting, bloody stools, etc., mainly due to disease-causing emboli and the anatomical structure of the superior mesenteric artery itself. 1. Disease-causing embolus: the embolus that causes embolism of the superior mesenteric artery mainly comes from the heart, such as the attached wall thrombus after myocardial infarction, the redundant organisms of rheumatic cardiac valvulopathy, the attached wall thrombus near the auricle of the heart, as well as the redundant organisms of the valves of the atrial fibrillation and subacute bacterial endocarditis, and so on. Rupture of atherosclerotic plaques in large arteries may lead to dislodgement of emboli or attached wall thrombi, which in turn may cause embolization of the superior mesenteric artery. Bacterial emboli from abscesses, sepsis, and dislodged tumor emboli may lead to superior mesenteric artery embolism. 2. Anatomical structure: other blood vessels and the abdominal aorta are at right angles to each other, and blood clots do not easily enter them. However, the angle between the superior mesenteric artery and the abdominal aorta is acute, and the direction of its travel is almost parallel to that of the aorta. Moreover, the diameter of the superior mesenteric artery is thicker, and the direction of blood flow is also the same as that of the abdominal aorta. The dislodged embolus may follow the direction of blood flow into the superior mesenteric artery and stagnate in the stenosis or bifurcation of the vessel, resulting in embolization of the superior mesenteric artery. The most common site of embolization is the middle colonic artery. In case of superior mesenteric artery thrombosis, patients are advised to go to the hospital as soon as possible for examination and targeted treatment after the doctor has clarified the cause of the disease.