High fasting blood glucose in the morning of diabetic patients may be caused by dawn phenomenon, Sumuje phenomenon and other conditions. 1. Dawn phenomenon: diabetic patients with stable blood glucose control at night, that is, there is no hypoglycemia, due to the imbalance of secretion of various hormones in the early morning, the body of glucagon, adrenaline and other glucagon increased, resulting in a state of high fasting blood glucose. 2. Sumujie phenomenon: that is, there is a hypoglycemic attack at night, so the body in order to protect itself to start the negative feedback regulation mechanism, making the body’s glucagon, growth hormone secretion increases, resulting in a rebound increase in blood glucose a phenomenon. Fasting blood sugar in the morning is higher than that in the evening, it is recommended to go to the hospital, so that the doctor combined with the specific situation to determine.