Fasting blood glucose 6.4mmol/L is high and abnormal for normal people; it is within the target range and normal for diabetic patients. 1. The normal value of fasting blood glucose for normal people is between 3.9~6.1mmol/L, so fasting blood glucose 6.4mmol/L is high, and it is recommended to consult a professional doctor for a clear diagnosis. 2. For patients who have been diagnosed with diabetes, fasting blood glucose should be controlled between 4.4~7.0mmol/L, so fasting blood glucose of 6.4mmol/L can reach the control target, and you can continue the current treatment program. Once the blood glucose level is found to be elevated, it is recommended to consult a doctor in time. Patients with abnormal blood glucose need to control their diet, avoid high intake of sugary foods, exercise appropriately, and monitor their blood glucose regularly.