Reticulocytes are newly produced, relatively immature red blood cells. They form and mature in the bone marrow before being released into the blood.
The reticulocyte test may be used: As a follow up to abnormal results on a complete blood count (CBC), RBC count, hemoglobin or hematocrit, to help determine the cause.
The normal fraction of reticulocytes in the blood depends on the clinical situation but is usually 0.5% to 2.5% in adults and 2% to 6% in infants. A reticulocyte percentage that is higher than “normal” can be a sign of anemia, but this depends on the health of a person’s bone marrow.
