The total white blood cell count of normal people is 4.0 ~10.0×109 (4000 ~10000/mm3) per liter of blood, and leukopenia is defined as below 4.0× 109/ liter (4000/mm3).

Drug action. Taking certain drugs can lead to leukopenia in the body. When taking these drugs, we should pay attention to check the white blood cells and platelets. If the white blood cells are too low, it is necessary to stop taking medicine or change medicine. The common drugs are: a, antibiotics, mainly chloramphenicol and synthetic mycin, which inhibit the hematopoietic function of bone marrow; Others such as tetracycline, polymyxin and streptomycin can also be used occasionally; B, anti-tumor drugs. When tumor cells are killed, normal tissue cells of human body are also damaged. C antipyretic and analgesic drugs (aminopyrine, metamizole, APC, phenylbutazone, indomethacin, etc. Are related to long-term use of large doses); D, antipsychotics (chlorpromazine, perphenazine, trifluoperazine); E, antithyroid drugs (propylthiouracil, tabazole, etc. ); Others: sulfanilamide, quinine, phenytoin sodium, phenobarbital, isoniazid, mercuric agent, antimony agent, etc.

Virus infection. Influenza, viral infection, viral hepatitis, etc. Can lead to low white blood cells. At this time, antiviral treatment should be actively carried out, and drugs that increase white blood cells can be taken as appropriate during the treatment.

3. Other diseases. Chemotherapy of various solid tumors, various hematological diseases, immune system diseases and some chemical factors may cause leukopenia.

The harm of low white blood cells:

Susceptible to infectious diseases. White blood cells can quickly swallow foreign bodies and produce antibodies, effectively resist the invasion of pathogens, and also play an important role in disease immunity. And if the human body's white blood cells are too low, it is easy to suffer from various infectious diseases, even some fatal infectious diseases.

Immune ability decreased. White blood cells are responsible for human immunity, and low white blood cells will reduce human immunity. Slight deficiency is called agranulocytosis, and severe deficiency (less than 1.5) is called agranulocytosis, which is very dangerous and will cause serious infection and death.

Physical discomfort symptoms. Low white blood cells generally lead to dizziness, fatigue, limb weakness, loss of appetite, low fever, insomnia and other nonspecific symptoms. A few patients are asymptomatic, and some patients have recurrent oral ulcer, lung infection or urinary tract infection. Leukopenia and agranulocytosis have a sudden onset and are often accompanied by high fever, chills, headache, fatigue or extreme weakness. Necrotic ulcers sometimes appear on mucous membranes such as mouth, nasal cavity, skin, rectum, anus and vagina. These uncomfortable symptoms have seriously affected the work and life of patients.