Chronically low white blood cells can increase the risk of cancer. This is because low white blood cells lead to a decrease in the body’s immunity, which can increase the risk of infections, including bacterial infections, fungal infections, viral infections, and infections with specific pathogens such as tuberculosis. Among them, special attention should be paid to viral infections, because research has now shown that many tumors are closely related to viral infections, for example, there is a virus called human T-cell leukemia virus, and patients infected with it have a high chance of developing T-cell leukemia; there is also EBV, and research has now shown that malignant tumors such as Burkitt’s lymphoma and nasopharyngeal carcinoma are closely related to EBV infections. Therefore, if a patient has low white blood cells for a long time, he or she should go to the hospital as soon as possible to check, clarify the cause and carry out relevant treatment to avoid adverse consequences.