The cause of leukemia is still unknown and may be related to many factors such as biological factors, physical factors, chemical factors, genetic factors, and the development of other diseases. 1. Biological factors: may be the main factors, including viral infections and abnormal immune function. Some people with abnormal immune function have an increased risk of developing leukemia. 2. Physical factors: Ionizing radiation such as X-rays and γ-rays may lead to leukemia when a large area is exposed to large doses. 3. Chemical factors: such as benzene and organic solvents containing benzene, ethylenediamine, and certain antitumor drugs. 4. Genetic factors: People with a family history of malignant neoplastic diseases may have a higher risk of developing leukemia. 5. Development of other diseases: Blood diseases such as myelodysplastic syndromes, lymphomas, multiple myeloma, etc. may eventually develop into leukemia. However, the above risk factors are not absolute factors leading to the development of leukemia, i.e., people exposed to these risk factors may not always develop leukemia, while people who are not exposed to the above risk factors may also suffer from leukemia. Prompt medical attention is recommended in case of discomfort.