A fasting blood sugar of 7.5 mmol/L is not necessarily diabetes. Diabetes mellitus is very common nowadays, and the diagnostic criteria are: first, there should be symptoms such as dry mouth, excessive drinking, excessive urination, and wasting. Secondly, diabetes can be diagnosed when fasting blood sugar is greater than or equal to 7.0mmol/L in the accompaniment of the above symptoms. Third, diabetes can also be diagnosed if the blood glucose two hours after meal or two hours in OGTT is greater than or equal to 11.1mmol/L. Fourth, diabetes can also be diagnosed if there are no symptoms mentioned above, as long as the fasting blood sugar is greater than or equal to 7.0 mmol/L. Therefore, if the fasting blood glucose is 7.5mmol/L, you need to see if there are any clinical symptoms. If there is dry mouth, excessive drinking, excessive urination, and the fasting blood sugar is greater than or equal to 7.0 mmol/L, then it is diabetes. This diagnosis is established. If there are no symptoms and the fasting blood glucose is greater than 7.0 mmol/L, that means that the fasting blood glucose is 7.5 mmol/L, and it needs to be measured again on another day. Diabetes can also be diagnosed if on both days, even if there are no symptoms, the fasting blood glucose is still greater than or equal to 7.0 mmol/L. The value of fasting blood glucose is based on the value of blood glucose in the vein.