Large fluctuations in blood glucose are prone to hypoglycemic reactions, as well as diabetic complications such as diabetic ketoacidosis, diabetic nephropathy, diabetic fundopathy, and other diabetic complications. 1. Hypoglycemia: large fluctuations in blood glucose can lead to hypoglycemia, hypoglycemia may induce angina pectoris, arrhythmia, myocardial infarction and other acute cardiovascular diseases; hypoglycemia for a long time will produce irreversible damage to the central nervous system, manifested as impaired consciousness, coma and so on. 2. Diabetic complications: large fluctuations in blood glucose can easily lead to a sharp rise in blood glucose, which is prone to diabetic ketoacidosis, hyperosmolar hyperglycemic coma and other acute complications, which are critical and life-threatening. Long-term blood glucose fluctuations can lead to various chronic complications of diabetes, diabetic nephropathy, diabetic retinopathy, diabetic peripheral neuropathy and diabetic foot and other complications. Patients with diabetes or abnormal blood glucose should control their sugar smoothly, minimize blood glucose fluctuations, and seek medical attention at any time if they have any discomfort.