For routine blood tests, you can either draw venous blood or take peripheral blood for examination. For adults and elderly people, venous blood is often taken, while for newborns and children, peripheral blood can be taken because venous blood is not easy to draw. After the blood is drawn, an anticoagulant is routinely placed inside the blood to prevent blood cells from coagulating, and then the test is performed in a routine blood test kit. It is possible to check the number of white blood cells, the number of red blood cells and the number of platelets, as well as the ratio of neutrophils, lymphocytes and monocytes within the white blood cells, and also the volume of red blood cells.