The normal range of white blood cells is 4~10×10^9/L, 20×10^9/L is high, usually caused by infection, tumor, tissue damage, etc., which can be treated by drugs (such as penicillin, cephalosporin), radiotherapy and so on. 1. Infection: If leukocyte 20×10^9/L is due to pathogen infection, then it can be treated with antibiotics empirically according to other symptoms, and then use antibiotics according to the target after doing drug sensitivity test, such as piperacillin, cefoperazone or other types of antibiotics. 2. Tumor: 20×10^9/L white blood cells can be seen in blood system diseases, such as leukemia, etc. In this case, patients need to undergo radiotherapy to control the relevant conditions after the white blood cells can return to normal. 3. Tissue damage: if the patient has recently had trauma and other tissue damage, may also lead to elevated white blood cells, such cases need to be treated according to the disease, to be damaged tissue healing or no longer cause inflammation, white blood cells can return to normal. White blood cells 20×10^9/L may also be caused by other reasons, the patient needs to consult a doctor in a timely manner, under the guidance of the doctor to improve the relevant examination, and targeted treatment. If you need to use drugs should be used under the guidance of a doctor, do not blindly use drugs.