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Hemoglobin Reticulocyte Count (with differential)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of young red blood cells (called reticulocytes) in your blood, which helps assess bone marrow production of red blood cells.

Quick summary

["Reticulocytes indicate how well your body is making new red blood cells."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
42810-2
Short code
Hgb Retic Qn
Synonyms
Hgb Retic Qn
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
12
Ref high
17.5
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85018
SNOMED
900000000000003004
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test to check for conditions affecting red blood cell production, such as anemia, bone marrow disorders, or response to treatments like chemotherapy or iron supplements. It can also help diagnose conditions like thalassemia or pernicious anemia.

What to Expect Before the Test

No special preparation is needed. The blood sample is typically drawn from a vein in your arm, similar to other blood tests. You may feel slight discomfort, but it usually lasts only a few minutes.

What the Results Mean

The test measures the absolute number of reticulocytes per microliter of blood. High reticulocyte counts may suggest increased red blood cell production, while low counts could indicate impaired bone marrow function or destruction of red blood cells.

Common Conditions Affecting Results

High reticulocyte counts can occur in conditions like hemolytic anemia, severe blood loss, or certain types of anemia. Low counts may be seen in aplastic anemia, bone marrow failure, or chronic kidney disease.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Reticulocyte Count

Frequently asked questions

How long does it take to get the results of this test?
Results are usually available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will discuss the findings with you during your follow-up visit.
Can I eat or drink anything before this test?
No dietary restrictions apply. You can eat and drink normally before the blood draw.
Is there any risk or side effect from this test?
The most common side effect is a slight bruise or soreness at the needle insertion site, which usually fades within a few days. Rarely, there may be mild swelling or pain. If you experience excessive bleeding or signs of infection, contact your doctor.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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