Aortic aneurysm is an abnormal local or diffuse dilatation of the aortic wall that causes symptoms by compression of surrounding organs, with aneurysmal rupture as its main risk. Aortic aneurysm symptoms: caused by aneurysm compression, pulling, and erosion of surrounding tissues, depending on the size and location of the aortic aneurysm. Thoracic aortic aneurysms cause coughing and shortness of breath when they compress the superior vena cava, coughing and shortness of breath when they compress the trachea and bronchi, difficulty swallowing when they compress the esophagus, and hoarseness when they compress the recurrent laryngeal nerve. Thoracic aortic aneurysms located in the ascending aorta may cause deformation of the aortic annulus and separation of the valve leaflets resulting in incomplete aortic valve closure and corresponding murmurs. Thoracic aortic aneurysms often cause pain, and a sudden increase in pain indicates the possibility of rupture. Aneurysms of the aortic arch compress the left innominate vein and may cause higher venous pressure in the left upper extremity than in the right upper extremity. Ascending aortic aneurysms may erode the sternum and rib cartilage and protrude into the anterior chest as a pulsating mass; descending aortic aneurysms may erode the transverse processes of the thoracic vertebrae and ribs and even protrude into the body surface in the back; pain is produced by bone invasion at all sites. Rupture of a thoracic aortic aneurysm into the bronchus, trachea, thoracic cavity, or pericardium can be fatal. Abdominal aortic aneurysms are common and can be asymptomatic, often with symptoms of renal, cerebral, and coronary atherosclerosis because the etiology is predominantly atherosclerotic. The initial attention is drawn to the presence of a pulsating mass in the abdomen. The more common symptom is abdominal pain, mostly located around the umbilicus or in the mid-upper abdomen, but may also involve the back. The onset and progression of pain indicates an enlarged aneurysm or a small amount of bleeding. Severe and persistent pain that extends to the back, pelvis, perineum, and lower extremities, or significant pressure pain over the mass, are signs of rupture. Abdominal aortic aneurysms often rupture into the left retroperitoneal space, followed by rupture into the abdominal cavity and occasionally into the duodenum or vena cava, with shock often occurring after rupture. Unless excessively obese, a pulsatile mass is usually not difficult to locate, usually between the umbilicus and the pubic bone, and sometimes a systolic murmur can be heard at the mass, rarely with tremor. Care must be taken when performing palpation of an aortic aneurysm, especially when pressure is present, to prevent prompting rupture. Compression of the iliac veins by abdominal aortic aneurysms may cause swelling of the lower extremities, compression of the spermatic veins may cause local varicose veins, and compression of one ureter may lead to hydronephrosis, pyelonephritis, and decreased renal function.