The five categories of blood count refer to the categorization and counting of white blood cells, the significance of which is that different white blood cell types indicate different diseases and assist in the diagnosis of diseases. There are five types of white blood cells, namely neutrophils, monocytes, lymphocytes, basophils and eosinophils. Neutrophils are the most numerous, followed by lymphocytes. Both total leukocytes and the individual classifications have a certain range of normal values and percentage of normal values, which, when abnormal, may suggest a certain disease to a certain extent. Neutrophilia is common in acute purulent infections and other diseases, and decrease is common in typhoid fever, influenza and other diseases; monocytosis is common in tuberculosis, typhoid fever and other diseases, and decrease is often meaningless; Lymphocytosis is commonly seen in diseases such as measles and mumps, and decrease is commonly seen in exposure to radiation, etc.; basophilia is commonly seen in allergy, and decrease is usually meaningless; eosinophilia is commonly seen in asthma, urticaria, and other diseases, and decrease is often meaningless. When the results of the five categories of blood routine are abnormal, it is necessary to consult the doctor in time and take treatment under the doctor’s guidance.