Blood picture is commonly known as the result of a routine blood test, which is a test of the number and shape of blood cells in the peripheral blood. The blood picture includes the number of white blood cells, the number and proportion of neutrophils, the number and proportion of lymphocytes, the number and proportion of eosinophils, the number and proportion of basophils, the number and proportion of monocytes, the number of red blood cells, hemoglobin concentration, red blood cell pressure, mean red blood cell volume, mean red blood cell hemoglobin volume, mean red blood cell hemoglobin concentration, reticulocyte number and proportion of red blood cells, number of platelets, platelet pressure volume, proportion of large and medium-sized platelets, etc. The blood test can provide a lot of clinical information for the diagnosis of diseases.