Adolescents can get chronic leukemia because acute and chronic leukemia are classified according to the time of onset and characteristics of the disease. Acute leukemia usually has a more rapid onset and progression, and the comorbidities appear earlier and are more severe, making treatment relatively difficult. For example, acute promyelocytic leukemia, combined with disseminated intravascular coagulation, can be fatal at any time. In addition, adolescents are not prohibited from chronic leukemia because of their young age. Chronic granulocytic leukemia, a common form of chronic leukemia, can be seen in adolescents. The onset of chronic granulocytic leukemia is characterized by a large spleen and abnormally high peripheral blood leukocytes, 100,000, 100,000 or even millions. Chronic leukemia is relatively gentle to treat and relatively difficult to treat. With early detection, early diagnosis and early treatment, adolescent chronic leukemia will not be at great risk and clinicians will treat the symptoms based on evidence.