Widening of the ascending aorta to greater than 50mm is dangerous. The internal diameter of the ascending aorta varies in different age groups. In adults, the normal diameter of the ascending aorta is less than 30 mm, and greater than 35 mm indicates widening of the ascending aorta. Common causes of widening of the ascending aorta are atherosclerosis, ascending aortic aneurysm, congenital anomalies, and infections. If the internal diameter of the ascending aorta is greater than 50 mm, an ascending aortic aneurysm is considered and there is a risk of rupture. The ascending aorta is located between the pulmonary trunk and the superior vena cava. Dilatation of the ascending aorta is associated with lesions of the middle layer of the aorta, where the elastic fibers become brittle and necrotic, losing their toughness and elasticity leading to damage of the arterial wall and eventually leading to gradual dilatation of the artery. Clinical manifestations include severe chest pain and high blood pressure. If the symptoms of chest tightness and chest pain are accompanied by a history of high blood pressure, one should go to the hospital promptly for examination to rule out ascending aortic lesions.