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 the types and proportions of white blood cells (differential count).
["A CBC helps doctors check for infections, anemia, bleeding disorders, or other blood-related conditions."]
Key facts at a glance
- LOINC
- 6294-3
- Short code
- Deprecated C3d-C3d+Gg-iC3b Recep EntNum WBC
- Synonyms
- Deprecated C3d-C3d+Gg-iC3b Recep EntNum WBC
- Category
- coagulation
- 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 Measure?
A CBC evaluates several key components: **Red Blood Cells (RBCs)** – carry oxygen throughout your body; **Hemoglobin** – the protein in RBCs that transports oxygen; **Hematocrit** – the percentage of blood volume made up of RBCs; **Platelets** – small blood cells that help prevent bleeding; and **White Blood Cells (WBCs)** – the immune system’s defenders. The **differential count** breaks down WBCs into subtypes (e.g., neutrophils, lymphocytes, monocytes) to assess immune function.
Why Might Your Doctor Order This Test?
A CBC is commonly used to diagnose or monitor conditions like anemia (low RBCs), infections (high WBCs), bleeding disorders (low platelets), or blood cancers. It’s also part of routine check-ups or before surgeries.
How Is This Test Performed?
A small blood sample is drawn from a vein (usually in your arm). The sample is sent to a lab, where machines analyze the cells and components. The differential count may require additional microscopic review.
What Do Results Mean?
Results show absolute counts (e.g., number of WBCs per microliter) and relative proportions (e.g., % of neutrophils). Abnormal values may signal infections, inflammation, or other health issues, but interpretation depends on your overall health and symptoms.
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.
Clinical Significance
Short name
CBC with Differential
Frequently asked questions
How often should I get a CBC?
What if my CBC shows low white blood cells?
Can diet 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