Myeloproliferative conditions can be categorized into five grades according to the degree of active proliferation: extremely active proliferation, markedly active proliferation, active proliferation, reduced proliferation, and extremely reduced proliferation. 1. Extremely active hyperplasia: exists in all kinds of myeloproliferative diseases and all kinds of typical acute and chronic leukemias, as well as after treatment with certain biologically active agents (human granulocyte stimulating factor). 2. Significantly active proliferation: present in various types of proliferative anemia, such as hemolytic anemia, iron deficiency anemia, acute blood loss, megaloblastic anemia, etc., bacterial infections, bone marrow reactions caused by drugs (prednisone), atypical acute and chronic leukemia, hypersplenism, myeloproliferative disorders, etc. 3. Active proliferation: present in diseases not originating in the hematopoietic system, early lymphoma, multiple myeloma, a few atypical leukemias, anemia, bacterial infections, and in healthy individuals. 4. Decreased proliferation: found in rare hypoproliferative leukemias and aplastic anemia. 5. Extremely reduced proliferation: found in aplastic anemia. Interpretation of specific indicators should be carried out under the supervision of a physician.