Red Blood Cell (RBC) Count with Differential Analysis (Specimen: Whole Blood)
This test measures the types and proportions of red blood cells and their fragments in your blood, helping identify abnormalities in blood cell production or function.
["Understanding your blood cell composition can help diagnose conditions like anemia, infections, or blood disorders."]
Key facts at a glance
- LOINC
- 104678-8
- Short code
- DMA 18:0/C18:0 RBC
- Synonyms
- DMA 18:0/C18:0 RBC
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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
What Is a Differential Count?
A differential count breaks down the total red blood cell count into five main types: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type has a distinct role in your immune system and overall health. The percentages of these cells can reveal clues about infections, inflammation, or other health issues.
Why Might You Need This Test?
Your doctor may order a differential count to check for blood disorders, such as leukemia or other cancers, or to monitor conditions like anemia, autoimmune diseases, or infections. It’s also useful before surgeries or during treatments that affect your blood cells.
How Is This Test Done?
A small blood sample is taken from a vein in your arm. The sample is then analyzed under a microscope to count and classify the different types of white blood cells and red blood cell fragments (reticulocytes). This process helps determine the health and balance of your blood cells.
What Does the Test Result Mean?
Results show the percentage of each cell type, which can help identify shifts in your immune response or blood health. For example, an unusually high number of one type of white blood cell might suggest an infection, while a low count could indicate a systemic issue.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A differential count is critical for diagnosing and managing conditions like infections (e.g., bacterial vs. viral), blood cancers (e.g., lymphoma, leukemia), and autoimmune diseases (e.g., lupus). It also guides treatment decisions, such as adjusting medications or planning blood transfusions.
Short name
RBC Differential
Frequently asked questions
What does a differential count measure?
How long does it take to get results from this test?
Can lifestyle changes affect my differential count?
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 17, 2026. · Read our editorial policy