An aortic internal diameter of 37 is usually abnormal. The normal adult ascending aortic internal diameter is less than 35 millimeters, 33 to 36 millimeters in men and 28 to 32 millimeters in women by gender. Below normal values is called aortic constriction, above normal values is called aortic dilatation, and typically greater than 45 is called aneurysmal dilatation. Echocardiography shows that the diameter of the ascending aorta is greater than 35 mm, indicating widening of the ascending aorta, which can be seen in many diseases, such as ascending aortic aneurysm, atherosclerosis, dilated cardiomyopathy, congenital malformations, etc., and the results of different diseases are not exactly the same. Aortic I.D. 37 requires prompt medical attention to identify the cause, and the patient needs to undergo further testing and aggressive control of risk factors, which can generally prevent further widening of the aortic diameter.