Complete Blood Count (CBC) with Differential
This test measures your blood’s overall health, including red blood cells, white blood cells, and platelets, along with a breakdown of different types of white blood cells.
["A CBC helps doctors diagnose and monitor conditions like infections, anemia, or blood disorders."]
Key facts at a glance
- LOINC
- 26464-8
- Short code
- WBC # Bld
- Synonyms
- WBC # Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- 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
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What Does a Complete Blood Count Measure?
A CBC includes several key components: Hemoglobin (Hb) measures oxygen-carrying red blood cells, Hematocrit (Hct) measures their volume, and Platelet Count tracks blood clotting cells. White Blood Cell (WBC) Count identifies immune system activity, while Red Blood Cell (RBC) Count assesses overall red blood cell health.
Why Is a White Blood Cell Differential Important?
The differential counts specific types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) to help pinpoint infections, inflammation, or immune system issues. For example, high neutrophils may signal bacterial infections, while high lymphocytes could indicate viral infections or chronic conditions.
How Is This Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The blood is then analyzed in a lab to count and identify different blood cell types using automated technology.
When Might You Need This Test?
Doctors often order a CBC with differential to check for infections, anemia, blood disorders (like leukemia), or to monitor chronic conditions such as diabetes or kidney disease.
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.
◆Associated findings1
Short name
CBC with WBC Differential
Frequently asked questions
What does a CBC with differential tell me about my immune system?
How often should I get this test?
Can lifestyle changes 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