The cause of leukemia is not yet clear and may be due to heredity, gene mutation, viral infection and other factors. Symptoms include anemia, bleeding, fatigue, low fever and so on. 1. Leukemia is a class of malignant clonal diseases of hematopoietic stem progenitor cells, which are arrested at different stages of cell development due to uncontrolled proliferation of leukemic cells, impaired differentiation, and impaired apoptosis. Currently, the causes of leukemia may be related to heredity, gene mutation, chemical stimulation, viral infection, ionizing radiation, bad life habits and other factors. 2. Leukemia starts at different stages and manifests itself in different symptoms. Early stage patients may have symptoms such as pale face and enlarged lymph nodes. Acute leukemia patients may have symptoms such as anemia, nosebleeds, gum bleeds, abnormal increase in menstruation, or joint pain and blurred vision. Patients with chronic leukemia may experience symptoms such as fatigue, low-grade fever, excessive sweating, weight loss, and emaciation. Once diagnosed with leukemia, patients need to actively cooperate with doctors to take relevant treatment measures to avoid delays.