Myelodysplastic syndromes (MDS) are a group of diverse bone marrow disorders in which the bone marrow does not produce enough healthy blood cells. Staging and classification of MDS are crucial for determining prognosis and guiding treatment decisions. The most commonly used classification systems for MDS are the French-American-British (FAB) classification and the World Health Organization (WHO) classification. The FAB classification, developed in the 1980s, divides MDS into five subtypes based on the percentage of blasts in the bone marrow and blood, and the presence of ring sideroblasts. These subtypes are: refractory anemia (RA), refractory anemia with ringed sideroblasts (RARS), refractory anemia with excess blasts (RAEB), refractory anemia with excess blasts in transformation (RAEB-T), and chronic myelomonocytic leukemia (CMML). The WHO classification, updated in 2016, provides a more detailed categorization and includes cytogenetic information. It recognizes six major subtypes of MDS: MDS with single lineage dysplasia (MDS-SLD), MDS with multilineage dysplasia (MDS-MLD), MDS with ring sideroblasts (MDS-RS) divided into MDS-RS with single lineage dysplasia (MDS-RS-SLD) and MDS-RS with multilineage dysplasia (MDS-RS-MLD), MDS with excess blasts (MDS-EB) divided into MDS-EB-1 and MDS-EB-2, MDS unclassifiable (MDS-U), and MDS associated with isolated del(5q). In addition to these classification systems, the International Prognostic Scoring System (IPSS) and its revised version (IPSS-R) are used to stage MDS and predict its course. These systems take into account factors such as the number of cytopenias, percentage of bone marrow blasts, and cytogenetic abnormalities. The IPSS-R further refines the cytogenetic risk categories and includes depth of cytopenias in the scoring system. The IPSS-R stratifies patients into five risk groups: very low, low, intermediate, high, and very high. Each group corresponds to a different median survival and risk of transformation to acute myeloid leukemia (AML). It's important to note that these classification and staging systems are not perfect and have limitations. They may not capture all the heterogeneity of MDS, and their predictive accuracy can vary among different patient populations. Nonetheless, they provide a useful framework for assessing patients with MDS and guiding clinical decision-making.