The causes of leukemia are not yet clear, but may be related to low immunity, hereditary factors, long-term ionizing radiation, chemical carcinogens, etc. 1. Low immunity: it may lead to certain viral infections or abnormal immune function, which may lead to leukemia. 2. Hereditary factors: for example, the incidence of leukemia will increase in patients with Down’s syndrome. 3. Long-term ionizing radiation: such as X-rays, γ-rays, etc., may also promote the occurrence of leukemia. 4. Long-term exposure to chemical carcinogens: e.g. benzene and its derivatives, certain antitumor drugs such as alkylating agents and other immunosuppressive agents. There may be other reasons for leukemia, such as myelodysplastic syndromes that are finally converted to acute leukemia. If there are high-risk factors or symptoms in this regard, it is recommended to go to the hospital in a timely manner to find out the cause of the disease and receive treatment under the guidance of a physician in order to avoid delays in the condition.