In general, low immature reticulocyte ratio may be caused by low hematopoietic function of bone marrow or the use of chemotherapy drugs. 1. Low bone marrow hematopoiesis: Low immature reticulocyte ratio may be caused by low bone marrow hematopoiesis. When there is a large number of abnormal cells infiltrating the bone marrow, it may lead to inhibition of red blood cell proliferation, and thus the number of immature reticulocytes may decrease. This condition is usually common in patients with aplastic anemia or leukemia. 2. Use of chemotherapeutic drugs: after using chemotherapeutic drugs, patients with malignant tumors may suffer damage to the hematopoietic stem cells of the human body. Therefore, some patients with malignant tumors may have low immature reticulocyte ratio after long-term chemotherapy. However, the immature reticulocyte ratio usually returns to normal some time after chemotherapy is completed, and no special treatment is needed. Low immature reticulocyte ratio may also be caused by other reasons, after the occurrence of the above situation, we need to consult the doctor in time, combined with other indicators, to comprehensively determine the cause, and symptomatic treatment.