The accuracy of measuring blood glucose is basically the same for the left and right hands. If it is testing fingertip blood, the accuracy rate of all ten fingers is also the same. Generally blood circulates in the organism, and the blood glucose value of each fingertip is roughly the same, only when choosing a finger, choose the part with a thin corneous layer, if the finger callus is too thick and the needle is too shallow, the blood glucose value read out will be inaccurate, so it is better to choose the ring finger, little finger and index finger. In the fasting state, the values of finger blood and venous blood are roughly similar. This is because although finger blood is a mixed fluid, mainly consisting of micro-arterial, micro-venous blood and tissue fluid, the sugar content of arterial blood is roughly the same as that of venous blood because no meal has been taken, so the effect is not significant. When testing fingertip blood, the needle prick should be slightly deeper, too shallow will result in too little bleeding and squeezing will easily cause tissue fluid to enter the tested blood drops and cause the test value to be inaccurate. In the process of testing, the first drop of blood is discarded and the second drop of blood is used for testing. While testing fingertip blood, it is better to go to the hospital for 2-3 months to have venous blood sampling to check fasting blood glucose, 2-hour postprandial blood glucose and glycated hemoglobin, and compare with fingertip blood to better monitor your blood glucose. If fasting blood glucose >7.2mmol/L or postprandial blood glucose reaches 11.1mmol/L is measured, diabetes can be diagnosed, and prompt medical consultation and diagnosis should be made.