Hematologic diseases are diseases that occur in the hematopoietic tissues and immune system of the human body, and the following are common: i. Red blood cell diseases, commonly various types of anemia, such as iron deficiency anemia, aplastic anemia, megaloblastic anemia, autoimmune hemolytic anemia, thalassemia, etc., and primary erythrocytosis. Leukocyte diseases, most commonly various types of leukemia, such as acute lymphoblastic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, chronic granulocytic leukemia, and granulocytic deficiency, etc. Immune system diseases, the most common ones are lymphoma, including Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, and multiple myeloma. Fourth, bleeding disorders, the common ones are vascular purpura, thrombocytopenic purpura, coagulation disorders, hemophilia, disseminated intravascular coagulation, etc.