There are many reasons for high blood sugar in the morning, including dawn phenomenon, insufficient dosage of hypoglycemic drugs, nighttime hypoglycemia, etc. which can cause blood sugar to rise in the morning. 1. Dawn phenomenon: It is due to the increased secretion of glucagon in the patient’s body at dawn, and the blood glucose increases accordingly. Patients can be treated comprehensively by eliminating mental burden, improving sleep quality, reasonable diet, exercise therapy and adjusting glucose-lowering program. 2. Insufficient dosage of hypoglycemic drugs: Insufficient dosage of hypoglycemic drugs can cause high blood glucose in the morning, and patients can control their blood glucose by reasonably increasing the types or dosage of drugs under the guidance of doctors. 3. Nocturnal hypoglycemia: morning high blood sugar may also be caused by the use of too high a dose of hypoglycemic drugs leading to nighttime hypoglycemia after the phenomenon of high blood sugar, the patient needs to be dealt with through a reasonable reduction in the dose of drugs. If morning hyperglycemia occurs frequently, it is recommended to measure the blood glucose from 0:00-4:00 a.m. to identify the above three situations, and adjust the medication under the guidance of the doctor according to the different situations.