Abdominal aortic aneurysm is not a tumor that grows in the abdomen, but the wall of the abdominal aorta is damaged, destroyed and denatured, resulting in the loss of elasticity of the arterial wall, and the diameter of the artery gradually stretches, expands, and bulges out longitudinally or transversely under the impact of the high-pressure flow of blood, and an abdominal aortic aneurysm is formed when the diameter is greater than 50% of the normal diameter. Who is susceptible to abdominal aortic aneurysm? The causes of abdominal aortic aneurysm are complex, but currently it is believed to be most closely related to atherosclerosis, but also related to congenital factors, genetic factors and metabolic factors. In the elderly, the degradation, fracture and calcification of elastic fibers in the aortic wall, excessive fat intake, and formation of atherosclerotic plaques in the arterial wall all contribute to the occurrence and development of abdominal aortic aneurysm. Many common diseases are also high-risk factors for abdominal aortic aneurysm: for example, high blood pressure promotes the hardening of arterial wall, which is more prone to dilatation; diabetes mellitus reduces the repair and reconstruction ability of arterial wall tissues, which makes it difficult to resist the attack of various disease-causing factors. In addition, after investigation and statistics, it is found that many tissue lesions in which the human body bears tension are closely related to abdominal aortic aneurysm, such as emphysema, chronic bronchitis, abdominal hernia and so on. We summarize the high incidence of abdominal aortic aneurysm as “eight high and one low”: high blood fat, high blood sugar, high uric acid, high body weight, high blood pressure, high (blood) viscosity, high age, high (mental) stress, and reduced exercise. In addition, smokers should pay attention to the fact that a large number of studies have shown that smoking is also one of the causes of abdominal aortic aneurysm. Other rare causes include cystic degeneration of the middle layer of the artery, syphilis, congenital dysplasia, trauma, infections, connective tissue diseases, etc.