Reticulocyte Count
The percentage of young red blood cells, showing how actively the bone marrow is producing new cells.
| Typical reference range | 0.5–2.5 % |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Reticulocytes are immature red cells released from the bone marrow that mature within about 1-2 days in circulation. Their percentage reflects the current rate of red cell production.
Why it matters
The reticulocyte count distinguishes anemia caused by underproduction (low count) from anemia caused by blood loss or destruction (high count), and shows response to iron or B12 treatment.
What a high result can mean
High counts occur with hemolysis, recent bleeding, recovery after treatment of iron, B12 or folate deficiency, and at altitude.
What a low result can mean
Low counts with anemia suggest underproduction from iron, B12 or folate deficiency, kidney disease (low erythropoietin), chronic inflammation or bone marrow suppression.
What affects the result
Interpret in relation to the degree of anemia (corrected reticulocyte count or absolute reticulocyte count). Recent blood donation raises it.
Unit
Usually reported in %.
Also called on lab reports
Reticulocytes, Retic Count, Reticulocyte %, Retic %, Reticulocyte Count, Automated
Related tests: Red Blood Cells
This page is educational and does not replace advice from a healthcare professional.