The five categories of routine blood tests mainly look at the indicators of white blood cells, red blood cells and platelets. Based on the test results, it can determine whether the body has anemia, infection, etc. It can also be used for the diagnosis of thrombocytosis, thrombocytopenia, leukopenia, aplastic anemia, etc. 1. White blood cells: including neutrophils, monocytes, lymphocytes, eosinophils and basophils. The results of leukocyte examination help to diagnose acute and chronic leukemia, and also determine whether the body has infections, infectious diseases, blood disorders, etc. 2. Red blood cells: including hemoglobin, width of red blood cell volume distribution, average red blood cell volume, average red blood cell hemoglobin content, average red blood cell hemoglobin concentration, etc. The results of red blood cell examination can assist in determining whether the body has anemia, erythrocytosis and other diseases; 3, platelets: including the average volume of platelets, platelet distribution width. It has a certain reference value for whether the body has iron deficiency anemia and whether there are platelet-related diseases. If there is abnormal thrombocytopenia, bone marrow aspiration is needed to exclude leukemia if necessary. Routine blood test is a blood test. Do not drink or overeat the day before the test, and you should avoid strenuous exercise and stress. If you need to check one of the indicators in the routine blood test for a long time, it is recommended to have the test at the same time. After blood sampling, you should gently press the blood collection area and not rub it too hard to avoid local hematoma and bruising.