Fasting blood glucose concentrations in healthy people are typically 3.9 to 6.1 mmol/L. Fasting blood glucose is usually measured in the morning and is usually fasted for at least 8 to 10 hours. If fasting blood glucose is higher than the upper limit of the normal range, it may be caused by factors such as diabetes, infection or stress, and needs to be taken seriously. In daily life, healthy people or diabetic patients should maintain a healthy diet, avoid eating a lot of fried food, cakes, milk tea, fatty meats and other high-fat, sugary foods, and appropriate physical exercise can help maintain stable blood glucose. When abnormal fasting blood glucose value occurs, it is recommended to go to the hospital and ask the doctor to make a judgment.