Symptoms of leukopenia vary depending on the condition and the primary disease, and may cause fatigue, malaise, dizziness, and even an increased risk of infection. Leukopenia is a condition in which the total number of leukocytes in the peripheral blood is consistently less than 4 x 10^9/L. It can be seen in the use of cytotoxic drugs, bone marrow suppression due to ionizing radiation, bone marrow hematopoietic disorders, infections, and autoimmune disorders such as systemic lupus erythematosus. Symptoms of leukopenia vary depending on the degree of decrease and the primary disease. In the case of mild reduction, the granulocyte defense function is hardly affected and there are usually no specific symptoms; in the case of moderate or severe reduction, non-specific symptoms such as fatigue, malaise, dizziness, loss of appetite, etc., are likely to occur, in addition to an elevated risk of infections. The body’s white blood cells play an important role in resisting the invasion of pathogens, when the white blood cells are severely reduced, the risk of infection rises, common respiratory tract infections, digestive tract infections, genitourinary tract infections, etc., and in severe cases, high fever or even infectious shock can occur. When persistent leukopenia is found clinically, it is recommended to go to the hematology department in time to clarify the cause of the disease, actively treat the primary disease, and also pay attention to the prevention of infection.