Consider the possibility of leukemia when there are abnormalities of white blood cells, platelets and hemoglobin in routine blood tests, but routine blood tests are not the diagnostic standard for leukemia. 1. Patients with leukemia may have significantly elevated leukocytes, decreased hemoglobin, decreased platelets, and abnormal classification of leukocytes, such as elevated lymphocytes or monocytes, and large unstained cells of unknown significance. 2. Primitive cells and promyelocytes in the peripheral blood of patients with acute leukemia may exceed 5%, while small lymphocytes of patients with chronic leukemia may exceed 80%, or basophils, neutrophils, eosinophils, and late granulocytes may appear in the peripheral blood. Although routine blood tests are suggestive for leukemia, the final diagnosis requires a bone marrow aspiration to confirm the diagnosis. Specific diagnosis and treatment should be carried out under the guidance of a physician.