Poor blood sugar control can have various serious consequences, as follows: 1, children’s diabetes: affect the growth and development of children; 2, pregnant women’s diabetes: poor blood sugar control can cause abnormal pregnancy, spontaneous abortion or fetal death in utero, abnormal development; 3, ordinary people’s diabetes: poor long-term blood sugar control in general can cause a variety of acute and chronic complications. If the blood sugar is seriously disturbed, acute complications of diabetes will occur in case of infection and stress, namely diabetic ketoacidosis, diabetic hyperglycemic hyperosmolar coma. Chronic hyperglycemia causes chronic complications of diabetes, which in turn lead to cardiovascular complications, diabetic foot, diabetic neurological complications, as well as diabetic nephropathy and diabetic retinopathy. In addition, poor glycemic control in diabetic patients can cause serious infections. Also diabetic patients have 2-3 times the risk of developing various tumors than non-diabetic patients.