Overview of Decreased Erythropoiesis By Gloria F Gerber, MD, Johns Hopkins School of Medicine, Division of Hematology Reviewed / Revised Jun 2023 View Patient Education Anemia, a decrease in the number of red blood cells (RBCs), hemoglobin (Hb) content, or hematocrit (Hct), can result from decreased RBC production (erythropoiesis), increased RBC destruction, blood loss, or a combination of these factors.