White Blood Cell Count with Automated Differential Analysis (Specimen: Whole Blood)
This test measures the total number of white blood cells (WBCs) in your blood and identifies the types and proportions of different white blood cell subtypes, which helps assess immune function and detect infections or inflammation.
["Your doctor may use this test to diagnose infections, monitor immune conditions, or check for blood disorders."]
Key facts at a glance
- LOINC
- 20584-9
- Short code
- WBC # Spec Auto
- Synonyms
- WBC # Spec Auto
- Category
- chemistry
- 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
- Method
- automated-count
- 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
Why This Test Matters for Your Health
White blood cells (WBCs) are crucial for fighting infections and protecting your body from illness. This test helps doctors understand if your immune system is working as it should, especially if you have symptoms like frequent infections, fatigue, or unexplained weight loss.
Types of White Blood Cells Analyzed
The automated differential counts specific types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type plays a unique role in your body’s immune response.
Common Reasons for Testing
Doctors order this test when you have symptoms like fever, swollen lymph nodes, frequent infections, or signs of inflammation. It may also be used during cancer treatment to monitor immune recovery or before surgeries to assess risk.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a blood sample. The process takes just a few minutes, and you can resume normal activities afterward.
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
WBC Auto Diff
Frequently asked questions
If your total WBC count is low, it may indicate immune deficiency or conditions like leukemia. If certain cell types are unusually high, it could signal infections, allergies, or autoimmune diseases. Doctors use these results to tailor treatments, such as antibiotics, medications, or lifestyle adjustments.
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the findings with you during your follow-up visit.
You can eat and drink normally before the test. No fasting is required, unlike some other blood tests.
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