There is no simple way to determine leukemia. The diagnosis of leukemia needs to be determined by its clinical manifestations, blood and bone marrow images, peripheral blood smears, and genetic tests. 1. Clinical manifestations: Because leukemia will lead to the reduction of three series, there will be related clinical manifestations, such as anemia due to the reduction of red blood cells, infection due to the reduction of white blood cells, and bleeding due to the reduction of platelets. Acute leukemia has sub sternal pressure pain. 2. Blood picture: in which red blood cells and hemoglobin are reduced. Most leukocytes are increased and the total number of leukocytes is also increased but most of them are sick leukocytes. Platelets are decreased, mostly down to 60×10⁹/L. 3. Bone marrow image: bone marrow proliferation is extremely active and abnormal proliferating cells can be seen, such as acute myeloid leukemia with a large number of primitive granulocytes. 4. Peripheral blood smear: primitive cells can be seen. 5. Genetic testing: leukemia can be accompanied by FLT3, RUNX1 and other gene mutations. The diagnosis of leukemia is a relatively rigorous matter, so there is no simplest method, the disease diagnosis needs to be carried out under the guidance of physicians.