In clinical blood tests, venous blood can be drawn for testing, or fingertip blood can be taken for testing, also known as peripheral blood testing. If the blood sampling method is taken correctly, generally speaking, there is no obvious error in the results of these two methods of blood sampling, but if the finger is excessively squeezed when taking fingertip blood, or the site of blood sampling happens to be lodged in the artery with a deeper location, the results of venous blood and fingertip blood will have certain errors. First of all, due to excessive squeezing, some of the tissue fluid will enter the blood specimen, the blood specimen may be diluted, and the number of various blood cells will be relatively reduced, whereas venous blood is more stable and most closely approximates the true cellular level of the body. A possible error between venous blood and fingertip blood is that the number of blood cells in the fingertip blood may be low.