A 50-year-old 7-year old diabetic with fasting blood glucose of 7.8 mmol/L should take his medication according to his usual routine and should not take additional medication without authorization, which may lead to nighttime hypoglycemia. If blood glucose is usually well controlled, the first thing to consider is the cause of the sudden rise in blood glucose, and take appropriate countermeasures according to the cause. Elevated blood glucose may be related to emotions, diet, or may be caused by medication factors. Emotional disorders will stimulate adrenaline secretion to increase, resulting in increased blood glucose, and the blood glucose will return to normal after the emotions are stabilized. If one eats too much, it will increase the free glucose in the blood so that the blood sugar rises. In the case of insufficient diet, the body will promote the isomerization of sugar, causing the situation of elevated blood sugar. Diet should be strictly controlled to avoid over and under eating and blood sugar will naturally return to normal. If you take too many hypoglycemic drugs or use too much insulin, it may also cause hypoglycemia followed by hyperglycemia. When diabetic patients stop using insulin or the drug dose is insufficient, reactive hyperglycemia will be produced due to hyperosmolar diuresis and dehydration caused by hyperglycemia, decrease in blood volume, and stimulation of adrenaline secretion. You should follow the doctor’s instructions to standardize the medication and not adjust the medication without authorization. Fifty-year-old patients with diabetes, if fasting blood glucose is persistently high, after excluding physiological reasons, should consult the doctor in time to avoid delaying the condition.