Myelodysplastic syndromes are a group of hematologic disorders with diverse clinical manifestations, pathophysiological and genetic alterations, clinically classified into at least five types, with two main categories, one with refractory anemia (60-80%), neutropenia or deficiency (50-60%) and neutrophil functional defects, and thrombocytopenia (40-60%), and progressive deterioration; the other major category is bone marrow in which The other major group has an excess of primary cells (5-20%) in the bone marrow, which are malignant cells. Both categories can be transformed into acute leukemia, which is close to leukemia and has the same nature of the disease as leukemia. These diseases are more frequent in middle-aged and elderly patients and are more difficult to treat. Essentially, they are diseases with clonal abnormalities of hematopoietic stem/progenitor cell development, with ineffective hematopoiesis and high myeloid leukemic transformation as their basic features.