Well-controlled diabetes can cause complications after ten years or more; if poorly controlled, complications can occur after a few months. Stabilized blood glucose affects the body relatively little, organ damage is less, and vascular health is maintained for a considerable period of time. Clinically, some patients will have complications after ten years due to decreased body functions or infections, and some patients will have no complications for life, which is the benefit of stabilizing blood glucose control. Poor glycemic control, failure to take medication as prescribed, and high and low blood glucose concentrations lead to abnormal fat metabolism, and the continuous deposition of various trace substances, or inflammatory factors in the blood vessels can cause the gradual formation of blood clots, which can cause even more damage to the tiny blood vessels. This situation will cause complications within a few months, such as hemorrhage in the fundus of the eye in the light case; in the heavy case, coma.