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White Blood Cell Count (WBC) with Differential Analysis (CBC with Differential)

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

This test measures the types and proportions of white blood cells in your blood, helping identify infections, inflammation, or other conditions.

Quick summary

["Understanding your immune response through blood cell types can guide treatment decisions."]

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

Key facts at a glance

LOINC
5539-2
Short code
Deprecated CD87 WBC-aCnc
Synonyms
Deprecated CD87 WBC-aCnc
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

Why This Test Is Done

Doctors order a white blood cell differential to diagnose infections (like bacterial or viral), check for immune disorders, monitor chronic conditions (e.g., leukemia, autoimmune diseases), or evaluate responses to treatments. It also helps assess symptoms like fever, fatigue, or unexplained weight loss.

What to Expect Before the Test

No special preparation is needed. You may have a simple blood draw from a vein in your arm. If you’re on blood thinners, let your doctor know to avoid unnecessary bleeding.

What the Results Mean

The differential breaks down white blood cells into categories (neutrophils, lymphocytes, monocytes, eosinophils, basophils) to show their relative counts. Abnormal levels may signal infections, allergies, or systemic diseases.

Common Conditions Linked to Abnormal Results

High neutrophil counts often point to bacterial infections or stress. Low lymphocyte counts may indicate immune suppression or certain cancers. Elevated eosinophils can suggest allergies or parasitic infections.

Reference range

Adult: 4.5-11.0 x 10^9/LN/A

Specimen: whole-blood

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

WBC differential

Frequently asked questions

What does a ‘differential’ mean in a blood test?
A differential refers to the breakdown of white blood cell types (neutrophils, lymphocytes, etc.) to assess immune health. It’s not the same as a total white blood cell count alone.
How often should I get a white blood cell differential test?
Only if your doctor recommends it—typically for monitoring chronic conditions, infections, or after treatments like chemotherapy. Follow your healthcare provider’s advice.
Can diet or exercise affect my white blood cell differential?
Diet and exercise generally don’t directly alter differential results, but they support overall immune function. Avoiding stress and infections is key for accurate 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