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Reticulocyte Count (Manual Count)

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

This test measures the number of young red blood cells, called reticulocytes, in your blood. Reticulocytes help assess your bone marrow’s ability to produce new red blood cells.

Quick summary

["Reticulocyte count helps diagnose and monitor conditions affecting red blood cell production."]

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

Key facts at a glance

LOINC
40665-2
Short code
Retics # Manual
Synonyms
Retics # Manual
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
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 Reticulocytes Matter in Blood Health

Reticulocytes are immature red blood cells released from your bone marrow to replace older cells. A higher-than-normal count may indicate your body is producing extra red cells, while a lower count could signal underproduction or destruction of red blood cells.

How the Test Works

This test involves a manual microscopic count of reticulocytes in a sample of your whole blood. Unlike automated tests, this method provides a more detailed assessment of early-stage red blood cell development.

When You Might Need This Test

Your doctor may order this test if you have symptoms like fatigue, pale skin, or shortness of breath, which can signal anemia or other blood disorders. It’s also used to evaluate bone marrow function before treatments like chemotherapy or radiation.

Common Conditions Affecting Reticulocyte Levels

High reticulocyte counts can occur in conditions like hemolytic anemia (where red blood cells are destroyed too quickly) or after blood loss. Low counts may suggest anemia from iron deficiency, vitamin B12 or folate deficiency, or bone marrow diseases like leukemia.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Reticulocyte Count as a Diagnostic Tool

Short name

Reticulocytes (Manual)

Frequently asked questions

What does a high reticulocyte count mean?
A high reticulocyte count often signals that your body is actively compensating for red blood cell loss, such as from bleeding, hemolysis, or increased production due to certain cancers or infections.
What does a low reticulocyte count mean?
A low reticulocyte count may indicate impaired bone marrow function, where your body isn’t producing enough new red blood cells, possibly due to deficiencies, chronic diseases, or medications that suppress marrow activity.
How often should I expect this test?
This test is typically ordered as part of a routine blood panel or when monitoring conditions like anemia, bone marrow disorders, or before certain treatments. Your doctor will determine the frequency based on your specific health needs.
  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