When the fingertip blood glucose is 5.6 mmol/L, the venous blood glucose is usually also around 5.6 mmol/L. The difference is not particularly large, but varies depending on the time of measurement and the instrument. Fingertip blood glucose is a frequently used method of monitoring blood glucose in people with diabetes. Since fingertip blood is a network of capillaries, there is both arterial and venous blood collected at the fingertips. In addition, the instruments used by diabetic patients may have errors due to the type of instrument, oxidization of test strips, etc., making it difficult to roughly estimate venous blood glucose values. If you want to know the value of your venous blood glucose, you can go to a regular hospital and have your blood tested to get a more accurate value.