Leukemia is commonly known as “blood cancer”, but is not a standardized name. It is a malignant hematologic disease that develops as a result of malignant cloning of hematopoietic stem cells by a variety of factors. The main feature of leukemia is the infiltration of leukemic cells into hematopoietic organs and tissues, which inhibits normal hematopoiesis in the body. The main clinical manifestations of leukemia patients include fever, bleeding, infection, and enlargement of the liver and spleen. According to the maturity of leukemia cells and the natural course of the disease, leukemia can be divided into acute leukemia and chronic leukemia. Acute leukemia is divided into acute myeloid leukemia and acute lymphoblastic leukemia; chronic leukemia is divided into chronic granulocytic leukemia and chronic lymphocytic leukemia. Depending on the age of the patient, leukemia can be divided into adult leukemia and pediatric leukemia. The cause of leukemia is currently unknown and may be related to long-term exposure to radiation or certain harmful substances (such as benzene), as well as to the use of certain drugs or genetics. The diagnosis of leukemia relies on blood work, bone marrow cytology, bone marrow biopsy, immunophenotyping, chromosomal and genetic tests. Although leukemia is relatively malignant and lethal, medical science has made great progress in recent years, and standardized treatment can control or even cure some patients, so once you have leukemia, you should actively cooperate with your doctor for standardized treatment and be prepared for a long-term battle with leukemia.