The average platelet volume is the average volume of each platelet in the peripheral blood. The normal range is 7-11fl, and anything below or above the normal range is considered abnormal. A lower average platelet volume often indicates poor bone marrow hematopoiesis, the most common disorders being aplastic anemia. There is also a decrease in platelet mean volume in patients with malignant tumors after chemotherapy and radiotherapy due to damage to hematopoietic stem cells. Increased average platelet volume is often due to excessive destruction of platelets in the peripheral blood and early release of larger platelets in the bone marrow that have not fully matured, the most common disease is immune thrombocytopenic purpura. Leukemia patients will experience a period of myelosuppression after chemotherapy. If the myelosuppression begins to resolve, a significant increase in the mean volume of platelets in the peripheral blood will occur, which often also represents the beginning of remission of the myelosuppression.