Reticulocyte Count (with or without Reticulocyte Index)
This test measures your blood’s immature red blood cells, called reticulocytes, which help assess your bone marrow’s ability to produce new red blood cells.
["Reticulocytes help diagnose anemia and monitor treatment effectiveness."]
Key facts at a glance
- LOINC
- 109891-2
- Short code
- Retics Msmt
- Synonyms
- Retics Msmt
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors order a reticulocyte count to check if your body is making enough red blood cells. It’s often used to diagnose conditions like anemia (low red blood cells) or to evaluate how well treatments like blood transfusions or medications are working. It can also help identify whether your bone marrow is functioning properly or if there’s an issue with your spleen’s role in red blood cell destruction.
What to Expect Before the Test
No special preparation is needed. You may have a simple blood draw from a vein in your arm, similar to other blood tests. If you’re on blood-thinning medications, let your doctor know before the test.
How the Test Works
Blood is taken and examined under a microscope to count reticulocytes, which appear slightly larger and have a network of ribosomes (visible as dots). Some labs may calculate a reticulocyte index to adjust for differences in red blood cell size.
What the Results Mean
Results are compared to your body’s needs and overall health. High reticulocyte counts may suggest anemia or blood loss, while low counts could indicate bone marrow problems or other conditions affecting red blood cell production.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High reticulocyte counts often point to **hemolytic anemia** (destruction of red blood cells) or **chronic blood loss**, while low counts may signal **bone marrow disorders** (e.g., aplastic anemia), **iron deficiency**, or **myelodysplastic syndromes**. The reticulocyte index helps distinguish between **ineffective erythropoiesis** (bone marrow producing immature, non-functional cells) and **true anemia from blood loss or hemolysis**.
Short name
Retic Count
Frequently asked questions
What causes a high reticulocyte count?
What causes a low reticulocyte count?
Can reticulocyte counts change with age?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy