Low large platelet ratio refers to the low percentage of large platelets in the blood, which needs to be judged together with other indicators and may be caused by myelodysplastic diseases, acute myeloid leukemia and other diseases. 1. Myelodysplastic diseases: low ratio of large platelets is related to myelodysplastic diseases, such as aplastic anemia. It is mainly manifested by anemia, infection and bleeding. With the continuous development of the disease, it may cause serious effects on the body and the risk of low large platelet ratio. 2. Acute myeloid leukemia: Acute myeloid leukemia is a common disease in hematology, which may be related to chemical, genetic, biological and other factors. When the disease occurs, leukemia cells will proliferate in the bone marrow, leading to the inhibition of normal hematopoietic function and the occurrence of low large platelet ratio. In case of low macroplatelet ratio, one should go to the hospital in time for medical consultation to identify the cause of the disease and then give appropriate treatment and therapy under the guidance of the doctor.