Blood routine generally take 2ml of blood is enough, take 20ml of blood may be used for a variety of tests, such as liver and kidney function, electrolytes, etc. 20ml is about 5-7 tubes, generally blood routine only need a tube of blood, need about 2ml. the examination content of white blood cells, neutrophils, lymphocytes, red blood cells, hemoglobin, platelets, etc. items. 1. The white blood cells mainly depend on the number, generally the increase represents infection and stress reaction, etc. The decrease can be seen in viral infection, blood disease, after radiotherapy and chemotherapy, etc. The neutrophils are usually elevated. 2. Elevated neutrophils are seen in inflammatory reactions such as cystitis and bronchitis, etc. Decreased neutrophils are seen in decreased immunity and viral infections. 3. Elevated lymphocytes are seen in viral infections such as influenza and hepatitis, etc. Decreases are seen in severe infections, immune disorders such as systemic lupus erythematosus, and in patients after radiation therapy. 4. Red blood cells are mainly seen in malnutrition and various types of anemia by their number and morphology. 5. High hemoglobin values are seen in children and long-term smokers, and lower values are seen in all types of anemia. 6. Elevated platelets are seen in hematologic diseases such as thrombocytosis and malignant tumors, while decreased values are seen in thrombocytopenic purpura and impaired bone marrow hematopoiesis. It is recommended that patients go to the laboratory of a regular hospital to have their blood drawn and go to the hematology department for consultation and treatment, and interpret the changes in the indexes under the guidance of a physician.