In addition to congenital developmental abnormalities, atherosclerosis, hypertension, and trauma can cause the middle layer to become less elastic and lose its toughness eventually leading to arterial dilatation. If the dilatation of the ascending aorta alone is mild, there is no symptom, and as the degree of dilatation increases, there will be transient chest tightness, and if it continues to develop, frequent chest tightness can occur. If the ascending aorta continues to dilate and evolves into an ascending aortic aneurysm, although it is a benign tumor, a tear in the lining will cause chest pain, and the pain is more intense and painful. If the condition is not controlled, loss of consciousness or sudden death may occur. Most of the dilated ascending aorta is secondary to hypertension, i.e. early treatment of the primary disease can stop its further development, and if the disease has already occurred it can be reviewed regularly and treated surgically if necessary.