Generally speaking, blood glucose testing can be done in seconds if blood is collected from the peripheral blood of the finger; if blood is drawn from a vein, it may take several hours to a day to test the blood glucose. Blood glucose is usually measured by blood collection, which is usually done in two forms: peripheral blood collection and venous blood collection. Blood glucose is measured from the peripheral blood of the fingertips, which is commonly used in daily life: this method is relatively time-consuming. Generally, after sterilization, use the special blood collection needle to puncture the skin, discard the first drop of blood, squeeze out another drop of blood, and then use the blood glucose meter and blood glucose test paper, it only takes about 10 seconds to get the blood glucose value. Since the blood glucose value from the peripheral blood of the fingertip is not very accurate, it is also necessary to draw venous blood for blood glucose testing for those who suspect diabetes, or to monitor the effectiveness of diabetes treatment. This test takes different amounts of time to produce results, depending on the processing capacity of each hospital’s laboratory, the number of specimens waiting to be tested, and so on. In general, venous blood glucose testing can take anywhere from a few hours to a day to produce a result. Currently, in order to diagnose diabetes mellitus, it is necessary to draw venous blood for fasting blood glucose, 2-hour postprandial blood glucose, and glycated hemoglobin, etc. Then, based on the results of the test, combined with clinical symptoms, a diagnosis is made, and treatment is carried out under the guidance of a doctor.