For clinical blood collection, peripheral blood and venous blood are different, of which venous blood is the most accurate and peripheral blood is worse. Because of the poor circulation of peripheral blood, the blood volume is less and often needs to be squeezed for blood collection, which will cause tissue fluid to exude and cause changes in the composition of the blood sample taken out, compared to the more stable and accurate test results of venous blood, which has greater reference significance for diagnosis and treatment. If you go for routine blood tests, it is recommended that venous blood be collected by means of phlebotomy. In the case of children or patients who have difficulties with venous blood collection, the use of peripheral blood is also possible, but the impact of peripheral blood on the results of blood tests should be taken into account, as well as the impact of the tests and the differences in their results.