There are mainly three reasons for leukopenia: the first is the impaired production of white blood cells, the second is the excessive destruction of white blood cells, and the third is the redistribution of white blood cells. Therefore, for leukopenia, the main approach is etiological treatment. If leukopenia is suspected to be caused by certain drugs or other pathogenic factors, generally, stopping the use of these drugs and avoiding contact can lead to the recovery of white blood cells to normal levels. For this kind of secondary decrease of white blood cells, we usually treat the primary disease. Once the symptoms of the primary disease are alleviated and controlled, the white blood cell count can return to normal without the need for additional medication. Moreover, the greatest risk of leukopenia is the fear of infection, but mildly reduced patients generally do not require special treatment. However, as the severity of leukopenia increases, the risk of infection increases, and at this point, some preventative measures against infection can be taken. Particularly for patients with neutropenia who are highly susceptible to severe infections, sterile isolation may be employed, and the specific sites and types of infections identified. This allows for the use of sensitive antibiotics; for viral infections, antiviral drugs can be administered. Additionally, broad-spectrum antibiotics capable of covering both Gram-negative and Gram-positive bacteria can be used. Furthermore, while preventing infection, it is also important to promote the production of granulocytes. This typically requires ruling out serious hematologic diseases before using medications that promote white blood cell production, such as B vitamins and squalene. However, these treatments are only symptomatic. The primary focus should still be on correcting the underlying cause to maintain white blood cells within a normal range. (Please consult a doctor before using any medication and do not self-medicate.)