Leukemia is a malignant tumor of the hematopoietic system that originates from hematopoietic stem/progenitor cells. It involves leukemia cells that have proliferative and survival advantages, proliferating and accumulating uncontrollably in the body, gradually replacing normal hematopoiesis to form pathological hematopoiesis. Furthermore, it invades other organs and systems, leading to symptoms such as anemia, bleeding, and infections, which eventually cause death. The incidence of leukemia is 4.8/100000-7.1/100000 in males and 3.2/100000-4.6/100000 in females, with significant variations in incidence, mortality rates, and distribution among different types of leukemia and various regions and ethnic groups. Early on, it was recognized that leukemia is not an inflammation, and the views that leukemia is caused by a lack of certain substances have been proven incorrect. Currently, it is understood that the causative factors of leukemia are related to infections, radiation, chemical agents, lifestyle, and genetics.