Reticulocytes

Reticulocytes are immature red blood cells that still contain remnants of the cell-manufacturing machinery. A reticulocyte count measures how many of these young cells your bone marrow is producing. This test reflects your bone marrow's ability to generate new red blood cells in response to anemia, blood loss, or hemolysis (red blood cell destruction). A high count suggests your marrow is working hard to replace lost cells, while a low count may indicate bone marrow disease or insufficient erythropoietin.