The white blood cell count is an important item in the blood routine and is the most commonly used clinical blood test: The normal value of the total white blood cell count is (3.5-9.5)*10^9/L. When the total white blood cell count is elevated (over 9.5*10^9/L), it is often seen in acute bacterial infectious diseases (such as acute tonsillitis, acute appendicitis, pneumonia, urinary tract infections, local abscesses, etc.), a few viral Infections (such as encephalitis B, measles), allergic reactions, after major surgery, burns, acute bleeding, drug poisoning, pesticide poisoning, tumors and blood diseases (such as leukemia), and some patients may also have elevated white blood cells after using certain drugs (leukocyte-elevating drugs, hormones, etc.). Wang Hao, Department of Traditional Chinese Medicine and Rheumatology, China-Japan Friendship Hospital Decreased total white blood cells (below 3.5*10^9/L) are often seen in viral infections (e.g. influenza, viral hepatitis, etc.), a few bacterial infections (e.g. typhoid and paratyphoid fever), blood disorders (aplastic anemia, etc.), post-radiation therapy, post-chemotherapy, hypersplenism, etc.