GLU generally refers to a blood glucose testing program, which mainly includes fasting blood glucose, 2-hour postprandial blood glucose, and random blood glucose. The full name of GLU is Glucose, which means glucose, so GLU is generally used as an abbreviation for blood glucose testing. Fasting blood glucose, is the value of blood glucose detected after not eating any calorie-containing diet for at least 8 hours. In general, the normal value of fasting blood glucose is ≥3.9 mmol/L but <6.1 mmol/L. If the fasting blood glucose is ≥6.1 mmol/L but <7.0 mmol/L, and the 2-hour postprandial blood glucose is <7.8 mmol/L, it is referred to as impaired fasting glucose, which is a sign of prediabetes. The 2-hour postprandial blood glucose is the blood glucose value measured 2 hours after the first bite of food. In general, 2-hour postprandial blood glucose should be <7.8 mmol/L. If 2-hour postprandial blood glucose is ≥7.8 mmol/L but <11.1 mmol/L, and fasting blood glucose is <7.0 mmol/L, it is known as impaired glucose tolerance, which is also a manifestation of prediabetes. If fasting blood glucose ≥7.0mmol/L, or random blood glucose ≥11.1mmol/L, or 2-hour postprandial blood glucose ≥11.1mmol/L, combined with symptoms of diabetes, such as dry mouth, excessive drinking, and excessive urination, it is called diabetes. A single abnormal blood glucose test does not indicate the problem, and it is necessary to consult a doctor in time, under the guidance of the doctor to test correctly, to make a clear diagnosis and timely treatment.