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Complete Blood Count with Differential (CBC with Differential)

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

This test measures the types and counts of cells in your blood, including red blood cells, white blood cells, and platelets, along with the proportions of different types of white blood cells.

Quick summary

Understanding your blood cell composition helps diagnose and monitor conditions like infections, anemia, or blood disorders.

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

Key facts at a glance

LOINC
64302-3
Short code
FULLTIMESOCIALWORKERSTAFFPOSITIONSFILLEDATENDOFPERIOD
Synonyms
—
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Cells Are Included?

Your blood contains several key components: red blood cells (RBCs), which carry oxygen; white blood cells (WBCs), which fight infections; and platelets, which help with clotting. The differential part breaks down the types of white blood cells into categories like neutrophils, lymphocytes, eosinophils, basophils, and monocytes.

Why This Test Matters in Your Care

A CBC with differential helps doctors assess your overall health, detect infections, identify anemia, or check for blood disorders like leukemia. It’s often used as a baseline test or to monitor conditions like chronic diseases.

How the Test Works

A small blood sample is taken from a vein, usually in your arm. The sample is then analyzed under a microscope to count and identify the different blood cells.

Common Uses and When It’s Ordered

This test is commonly ordered for routine check-ups, before surgeries, to monitor chronic illnesses, or when symptoms like fatigue, frequent infections, or easy bruising appear.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal results may indicate conditions such as infections (elevated WBCs), anemia (low RBCs), or clotting disorders (low platelets). Specific cell counts can also reveal immune system issues, bone marrow problems, or other systemic diseases.

Short name

CBC with Differential

Frequently asked questions

What does a CBC with differential measure?
It measures the total counts of red blood cells, white blood cells, and platelets, as well as the proportions of different types of white blood cells (differential count).
Why might my doctor order this test?
Your doctor may order this test to check for infections, anemia, blood disorders, or to monitor your health before treatments like chemotherapy or surgery.
What are the typical reference ranges?
Reference ranges vary by lab and individual, but general guidelines include RBC counts, WBC counts, platelet counts, and differential percentages (e.g., neutrophils 40–70%, lymphocytes 20–40%). Always ask your provider for your specific results.
  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