How much is the difference between fingertip blood sugar value and venous blood sugar value?

10%~ 15%。 Fingertip blood is a mixed liquid, including arterioles, venules and interstitial fluid. The venous blood glucose test is pure venous blood glucose. In the fasting state, fingertip blood is similar to venous blood sugar. This is because the difference between arterial blood glucose and venous blood glucose is very small in fasting state. At this time, compared with venous blood glucose, the difference is relatively small, and the general error is within 10%, which is regarded as normal. However, two hours after meals, due to the participation of arterial blood, the blood glucose level will be slightly higher than the venous blood glucose level, but it is generally between 10%- 15%.