In most cases, leukemia can be detected by routine blood tests, and there are two clinical types of leukemia: acute leukemia and chronic leukemia. For patients with chronic leukemia, it is divided into chronic lymphocytic leukemia and chronic granulocytic leukemia. In both types of chronic leukemia, a significant increase in the number of leukocytes in the peripheral blood can be detected through routine blood tests. In patients with chronic granulocytic leukemia, the increase in neutrophils is often evident, and in patients with chronic lymphocytic leukemia, the increase in lymphocytes is often evident. Therefore, a clear diagnosis of chronic leukemia can be made through routine blood tests, but most patients with acute leukemia also have a clear indication through routine blood tests that the patient will have a significantly higher number of white blood cells, often accompanied by anemia and thrombocytopenia. However, there are exceptions, such as a rare clinical form of hypoproliferative leukemia, which is more common in older patients and resembles aplastic anemia in the blood work. In addition, some patients with acute promyelocytic leukemia also show a reduction of the trilineage in the peripheral blood, which also needs to be differentiated from aplastic anemia. Therefore, in most cases, leukemia can be detected by having a blood routine.