Fasting blood glucose 6.3mmol/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 6.3mmol/L is high, and it is recommended to consult a professional physician for a clear diagnosis. 2. For patients who have been diagnosed with diabetes in the past, the general fasting blood glucose needs to be controlled between 4.4~7.0mmol/L, so the fasting blood glucose of 6.3mmol/L is to reach the control target, and you can continue the current treatment program. Once elevated blood glucose levels are detected, prompt medical attention is recommended. Patients with abnormal blood glucose need to control their diet, avoid high intake of sugary foods, exercise appropriately, and monitor their blood glucose regularly.