RDW: Definition and importance in blood test
RDW, acronym for Red Cell Distribution Width, is an index of erythrocyte anisocytosis and which represents the heterogeneity of distribution of the size of red blood cells. This size variation is called anisocytosis, and the value considered normal in adults and children varies between 11.6 and 14.5%. The RDW index is generally used to detect different types of anemia, because in the automated blood count, it represents the presence of anisocytosis or variation in the size of erythrocytes. Such an alteration can occur for several reasons, from anemia to the presence of chronic diseases, leukemia and use of medications. According to Bessman, et.al.; RDW may contribute to the differentiation between microcytic and hypochromic anemias. The evaluation should be done in conjunction with other indices such as MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Hemoglobin), MCHC (Mean Corpuscular Hemoglobin Concentration) and RDW. Various hematology analyzers such as the Erba 3/5 PDA serie