Complete Blood Count with Differential (CBC with Differential)
This test measures your blood’s red blood cells, white blood cells, and platelets, along with the proportions of different types of white blood cells (the differential). It helps assess overall health, detect infections, anemia, or blood disorders.
["A CBC with differential helps diagnose and monitor conditions like infections, anemia, or blood clotting issues."]
Key facts at a glance
- LOINC
- 4525-2
- Short code
- MCP C3b-C4b EntNum WBC
- Synonyms
- MCP C3b-C4b EntNum WBC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85004
- SNOMED
- 900000000000003002
- 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
What Does a CBC with Differential Measure?
Your blood sample is analyzed to count and identify three main cell types: red blood cells (RBCs), white blood cells (WBCs), and platelets. The differential counts the five types of white blood cells—neutrophils, lymphocytes, monocytes, eosinophils, and basophils—to help pinpoint specific health concerns.
Why Is the Differential Important?
The differential helps doctors determine the type and severity of infections (e.g., bacterial vs. viral), evaluate immune function, or check for conditions like leukemia or autoimmune diseases.
How Is This Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The sample is then processed in a lab to count and classify cells under a microscope or using automated technology.
What Might Abnormal Results Indicate?
Low or high counts of certain white blood cells can signal infections, inflammatory diseases, or immune system disorders. Elevated neutrophils might indicate bacterial infections, while low lymphocytes could suggest immune suppression.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A CBC with differential is a foundational test used in routine checkups, diagnosing infections, monitoring chronic conditions (e.g., cancer, autoimmune diseases), and guiding treatment decisions. It provides critical insights into blood health and systemic responses to illness.
Short name
CBC with WBC differential
Frequently asked questions
What does a high or low white blood cell count mean?
How often should I get a CBC with differential?
Can diet or medications affect my CBC results?
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