Although theoretically, insulin pumps are suitable for any diabetic patient who has hypo-insulin secretion. However, since insulin pumps are not yet covered by medical insurance, are relatively expensive and have some complexity in operation, they are mainly recommended for patients with brittle diabetes who are relatively young, have a strong ability to take care of themselves and have almost complete loss of insulin secretion function. How can we tell that a patient has brittle diabetes with almost complete loss of insulin secretion? These patients usually use subcutaneous insulin injection several times a day, but their blood glucose fluctuates greatly, and when the same dose of insulin is injected, fasting blood glucose is hyperglycemic (higher than 15 mmol/L) at one time and hypoglycemic (lower than 4 mmol/L) at another time; moreover, it is difficult to adjust the insulin dose, and hypoglycemia occurs when one unit is increased and hyperglycemia occurs when one unit is decreased. The figure below shows the dynamic glucose profile of a brittle diabetic patient before using the pump. It is well known that long-term hyperglycemia can lead to chronic complications of diabetes, so some brittle diabetic patients keep increasing insulin dosage by themselves in order to control hyperglycemia, resulting in frequent hypoglycemia, and the patients have no aura reaction such as hunger, panic and cold sweat when hypoglycemia occurs. In fact, this kind of frequent unconscious hypoglycemia is more dangerous than hyperglycemia. The unconscious hypoglycemia indicates that the patient is often in the state of hypoglycemia, and the body has adapted to the hypoglycemia and no longer produces the aura reaction. In this way, mild hypoglycemia is not detected and corrected in time, and often develops into severe hypoglycemia and even leads to mental disorder, blurred consciousness and coma before being detected. Long-term repeated severe hypoglycemia can stimulate the cardiovascular system, inducing arrhythmia and myocardial infarction, and can also lead to irreversible damage to the central nervous system, triggering strokes, etc. Patients who have been in hypoglycemic coma for too long and have not been corrected may become vegetative or even die. Therefore, for these brittle diabetic patients, subcutaneous insulin injections several times a day can hardly meet the requirements of blood glucose control, and insulin pump may be the treatment method necessary to control blood glucose and protect life and health. If the efficacy of insulin pump is ideal, it can basically eliminate the hypoglycemia of patients, and at the same time can make the blood glucose of the whole day basically controlled within the range of 5-12mmol/L. Individual patients with excellent cooperation can have their blood glucose controlled in the range of 5-10 mmol/L throughout the day. The figure below shows the dynamic blood glucose profile of a fragile diabetic patient after using the pump.