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

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

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

Quick summary

["Understanding your white blood cell types can help diagnose health issues early."]

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

Key facts at a glance

LOINC
5543-4
Short code
Deprecated CD91 WBC-aCnc
Synonyms
Deprecated CD91 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 Matters

White blood cells (WBCs) are crucial for fighting infections and maintaining immune health. This qualitative test provides a general overview of your WBC types, which can help doctors assess whether you have an infection, inflammation, or another condition affecting your immune system.

How the Test Works

A small sample of your blood is examined under a microscope. The test identifies and categorizes different types of WBCs, such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils, to determine their relative proportions.

Common Reasons for Testing

Doctors may order this test if you have symptoms like frequent infections, unexplained fevers, fatigue, or signs of immune dysfunction. It can also be used to monitor conditions like leukemia, autoimmune diseases, or reactions to medications.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or hand to draw blood. If you’re on blood-thinning medication, let your doctor know before the test.

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.

Clinical Significance

Short name

WBC Qualitative

Frequently asked questions

What Does a High or Low WBC Count Mean?
A high WBC count may indicate an infection, inflammation, or stress response. A low WBC count could suggest immune suppression, certain cancers, or other health issues. The specific types of WBCs can also provide clues about underlying conditions.
How Often Should I Get This Test?
Your doctor will determine how often you need this test based on your health status, symptoms, or ongoing treatment. Regular monitoring may be recommended if you have chronic conditions or are undergoing treatment for immune-related disorders.
Can I Eat or Drink Before the Test?
You can eat and drink normally before the test, as it does not require fasting. However, inform your doctor about any medications you’re taking, especially blood thinners, to ensure safe blood collection.
  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