Reticulocytes are immature red blood cells that have just been released from the bone marrow into the bloodstream. This test measures the percentage of reticulocytes in the blood, which provides important information about the bone marrow's ability to produce new red blood cells. Elevated reticulocyte counts indicate increased red blood cell production, commonly seen in conditions like acute or chronic blood loss, hemolytic anemias, or during recovery from anemia. Low reticulocyte counts suggest decreased red blood cell production, which can occur in bone marrow disorders, nutritional deficiencies, or certain chronic diseases. This test is particularly valuable for evaluating the response to treatment for anemia, as an increase in reticulocytes indicates that the bone marrow is responding appropriately to therapy. The reticulocyte count helps distinguish between different types of anemia and guides treatment decisions.