Reticulocytes
Disclaimer: Information on this page is for educational purposes. Consult a physician to interpret your test results. Health Vault helps track biomarker trends but does not replace medical advice.
What This Test Measures
Reticulocytes are immature red blood cells recently released from bone marrow. Their count reflects erythropoietic activity and the body's ability to compensate for anemia.
Reticulocytosis indicates regenerative anemia: after blood loss, in hemolysis, or during iron/B12 therapy. Low reticulocytes with anemia suggest inadequate bone marrow response.
Reticulocyte count is key to differentiating production versus destruction/loss anemias.
Normal Ranges
| Group | Reference Range |
|---|---|
| Men | 0.5–2.0% (25–75 × 10⁹/L) |
| Women | 0.5–2.0% (25–75 × 10⁹/L) |
| Children | 0.5–3.0% |
Reference ranges may vary by laboratory and assay method.
Causes of High Levels
- Hemolytic anemia
- Acute blood loss
- Recovery during iron/B12 therapy
- High altitude
- Post-splenectomy
Causes of Low Levels
- Aplastic anemia
- Iron/B12/folate deficiency (early stage)
- Chronic kidney disease
- Bone marrow infiltration
- Hypothyroidism
Test Preparation
- No preparation required
- Report recent transfusion (results may be distorted)
Related Biomarkers
| Biomarker | Relationship |
|---|---|
| Hemoglobin | Anemia severity |
| Red Blood Cells | Mature red blood cells |
| Iron | Substrate for erythropoiesis |
FAQ
How often should I take this test?
With anemia — at initial diagnosis and treatment monitoring (every 2–4 weeks).
What should I do if my result is abnormal?
High reticulocytes with low Hb — seek hemolysis or blood loss. Low — evaluate bone marrow.
Last updated: June 2026