What is abdominal aortic aneurysm? When we first talk to patients, many people’s first feeling is that this must be a malignant tumor, and they immediately look nervous, and the first concern is whether the disease can be cured and whether it will recur. In fact, abdominal aortic aneurysm refers to the aneurysmal expansion of the abdominal aorta, which is usually defined as an aneurysm with an increase of more than 50% in diameter, and according to the definition, it is easy to see that the so-called abdominal aortic aneurysm is actually an abnormal expansion of the human arterial vasculature due to certain factors. Other rare causes include mid-artery cystic degeneration, syphilis, congenital dysplasia, trauma, infection, and connective tissue disease. Common causative risk factors for abdominal aortic aneurysms include: smoking, hypertension, advanced age, and male gender. Smoking, in particular, also significantly increases the risk of aneurysm rupture. The vast majority of abdominal aortic aneurysms are lesions below the level of the renal arteries.