Type 1 diabetes, also known as insulin-dependent diabetes, is primarily due to an absolute deficiency of insulin. It is caused by the inability to produce islets on its own, which leads to elevated blood sugar. In general, diabetes alone does not cause death and can lead to long-term survival if the blood sugar is well controlled. However, because acute elevation of blood glucose can induce diabetic hyperosmolar coma and ketoacidosis, these two acute complications can lead to death if not actively and effectively managed. In the long term, elevated blood glucose can induce a variety of cardiovascular and cerebrovascular complications such as cerebral infarction and heart attack, and the chronic complications have a high disability and mortality rate. An effective way to prevent death and complications is to use insulin replacement therapy. Patients need to determine insulin dosage and type according to blood glucose monitoring, reasonable diet. Keep blood glucose within the normal range.