Blood routine is a method of checking the number, shape and proportion of blood cells in human peripheral blood through a blood cell analyzer. In order to understand the routine blood test sheet, we must first understand what the normal range of the number, shape and proportion of various blood cells is. The first item, the number of human white blood cells, to see if the test value is within the normal range, if the number of white blood cells increased, often seen in a variety of inflammatory diseases, cell count reduction can be seen in viral infections, tumor patients after receiving radiation therapy chemotherapy and bone marrow when the bone marrow suppression. The second item is the number of red blood cells. A decrease in the number of red blood cells is common in various anemic diseases, while an increase in the number of red blood cells is seen in chronic hypoxic diseases and myeloproliferative diseases, such as true erythropoietic disease. The third item, the number of platelets, the decrease in the number of blood cells is seen in immune thrombocytopenic purpura, also seen in aplastic anemia, leukemia, etc. A common cause of increased platelet count is primary thrombocytosis.