Diabetic blood glucose 18mmol / L, both fasting blood glucose, 2 hours after meal blood glucose or random blood glucose are obviously out of the normal range, belong to the elevated. The normal value of fasting blood glucose is 3.9-6.1mmol/L, the normal value of 2-hour postprandial blood glucose is <7.8mmol/L, and the random blood glucose is <11.1mmol/L. Generally, the target value of blood glucose control in diabetic patients is fasting blood glucose ≤7mmol/L, and the blood glucose of 2-hour postprandial blood glucose ≤10mmol/L. Diabetic patients with blood glucose of 18mmol/L are relatively high, and their blood glucose control is poor. control is poor. Blood glucose 18mmol/L is more dangerous, there is a risk of diabetic ketoacidosis and hyperglycemic hyperosmolar state; long-term poor glycemic control, but also a variety of chronic complications, such as diabetic nephropathy, retinopathy, diabetic neuropathy, diabetic foot and so on. Blood glucose 18mmol / L need to go to the hospital in time, under the guidance of the doctor to avoid delay.