Routine blood tests are arguably the most basic test in a hospital. It is even more common in our anti-infection clinic. It is done for fever, cough, dizziness and headache, nausea and vomiting, back pain and weakness, and so on. The cost of the test is not high, about 20 yuan, but it can help explain a lot of problems. Some people who consult about cough and fever tend to pay more attention to the results of chest CT and neglect to list the routine blood tests for the doctor to see. The following is an introduction to the important items in the routine blood tests for your reference. It is important to emphasize that all the tests need to be combined with medical history, so if you are not a professional doctor, you should not make a diagnosis, even if you can understand the meaning of each item – but it does not work. There are a lot of items in the routine blood test list, which will not vary much from hospital to hospital, and may differ slightly due to different instruments, but the basic items are still there, and each item will give two columns of test results and reference values, and the reference values given by different hospitals may have slight differences, but the fluctuations will not be too great. The three most important items to look at are: white blood cells (WBC), red blood cells (RBC), hematocrit (HGB), and platelets (PLT). Therefore, if a patient with fever has elevated WBC, PCT, ESR and CRP are usually added to assist in the diagnosis of such infections. In addition, other diseases such as leukemia may also be elevated, and their decrease may be due to hypersplenism or drug effects, etc. 2. Red blood cells and hematocrit: these two are combined to see if there is anemia. If RBC and HGB are below the lower limit of the reference value, “anemia investigation” is considered. The latter MCV, MCHC and MCH can often provide valuable information about the cause of the disease. 3, platelets: less than the normal value, suggesting a bleeding tendency, the causes are more common, caused by blood system diseases, such as thrombocytopenic purpura. In addition, combined with the examination of coagulation function, if there is a suggestion of severe bleeding tendency, surgery is not allowed, including various punctures and interventions are not allowed. 4, neutrophil count and neutrophil percentage: the two combined, elevated neutrophil percentage, generally speaking, suggests that the infection is bacterial may be large, but in addition to this granulocytic leukemia and other diseases can also cause it to rise. 5, lymphocyte count and lymphocyte percentage: the combination of the two, the lymph percentage is elevated, if the infection is viral may be large, may also be lymphocytic leukemia, its reduction may exist immune deficiency and other possibilities. 6, eosinophil count and eosinophil percentage: less used than the previous ones, its value is elevated to suggest the possibility of parasitic infection, drug allergies can also appear this ratio is elevated. Special emphasis is placed on the fact that each item is not isolated, sometimes multiple items need to be combined to be meaningful, in addition, depending on the gender and age of the patient, the test results may also have different significance.