Reticulocyte Count
Reviewed
Also called: Reticulocyte Percent, Reticulocyte Index, Corrected Reticulocyte, Reticulocyte Production Index, RPI
A reticulocyte count (retic count) measures the number of reticulocytes in your blood.
Specimen: Blood
Why this test may be ordered
- To help diagnose specific types of anemia
- To see if treatment for anemia is working
- To check if bone marrow is producing the right amount of red blood cells
- To check bone marrow function after chemotherapy or a bone marrow transplant
- To evaluate a newborn for hemolytic disease of the newborn (HDN)
Preparation and collection
You don't need any special preparations for a reticulocyte count test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes. To test a newborn, a health care provider will clean your baby's heel with alcohol and poke the heel with a small needle.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. There is very little risk to your baby with a needle stick test.
Understanding results
To understand the results of a reticulocyte count test, your provider will consider your symptoms, medical history, and the results of other blood tests.
- Higher-than-normal reticulocyte count (reticulocytosis): If your results show a higher-than-normal reticulocyte count (reticulocytosis), it may mean: You have hemolytic anemia, a type of anemia in which red blood cells are destroyed faster than the bone marrow can replace them. You have had new or ongoing bleeding (hemorrhage), and your body is making many more red blood cells to replace what you've lost. Limitation: If your reticulocyte test results were not normal, it doesn't always mean you have anemia or another health condition. Your reticulocyte counts may be higher during pregnancy. Next step: If you have questions about your results or your child's results, talk to your health care provider.
- Lower-than-normal reticulocyte count: If your results show a lower-than-normal reticulocyte count, it may mean you have: Iron deficiency anemia, the most common type of anemia. Aplastic anemia, an uncommon type of anemia, happens when the bone marrow isn't able to make enough blood cells. Bone marrow failure, which may be caused by an infection or cancer. Limitation: Some medicines may increase or decrease your reticulocyte count. Next step: If you have questions about your results or your child's results, talk to your health care provider.
- Results must be interpreted by a healthcare professional in the context of your symptoms, medical history, and other blood tests.
- A reticulocyte count that is not normal does not always mean you have anemia or another health condition.
- Reticulocyte counts may be higher during pregnancy.
- Counts may temporarily increase after moving to a high altitude and return to normal once your body adjusts.
- Some medicines may increase or decrease your reticulocyte count.
What to do next
If you have questions about your results or your child's results, talk to your health care provider.
- What do my reticulocyte count results mean in my specific situation?
- Do I need any other tests to confirm a diagnosis?
- What are the next steps if my results are not normal?
- Could any medications I am taking affect my reticulocyte count?
- How will my treatment be adjusted based on these results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.