Platelet macrocyte ratio generally refers to the ratio of large platelets. Elevated platelet counts may be caused by primary thrombocythemia, hemolytic anemia, chronic granulocytic leukemia, true erythrocytosis, and acute hemorrhage. 1. Primary thrombocythemia: It is a clonal disease of pluripotent stem cells, in which the bone marrow megakaryocytes will over proliferate, and the platelets will continue to increase significantly, and there may be recurrent bleeding from the skin and mucous membranes, and enlargement of the spleen, etc. As a result, the macroplatelet ratio will be elevated. This results in an elevated macroplatelet ratio. 2. Hemolytic anemia: A type of anemia that occurs when the rate of red blood cell destruction increases and the bone marrow hematopoietic function is insufficiently compensated. Symptoms such as chills, fever, anemia, jaundice, and hemoglobinuria may occur. When hemolysis is severe, it may be accompanied by splenomegaly, dyspnea, and elevated macroplatelet ratio. 3. Chronic granulocytic leukemia: It is a blood disease that affects the pluripotent hematopoietic stem cells of the blood and bone marrow. It is often characterized by thrombocytosis and splenomegaly, and may cause an elevated macroplatelet ratio. 4. True erythrocytosis: It is a chronic myeloproliferative neoplasm, which is characterized by abnormal increase in the number of red blood cells, increased blood viscosity, slowing down of blood flow and headache, which further leads to elevated large platelet ratio. 5. Acute hemorrhage: no matter whether the acute hemorrhage is caused by trauma or surgery, there will be symptoms such as pale face, thin pulse, darkness in front of the eyes, shortness of breath and elevated platelet count. Once the platelet ratio is elevated, you should go to the hematology department of the hospital immediately to identify the cause of the disease and get timely treatment.