Total White Blood Cell Count (WBC) with Differential (Serum/Plasma Specimen)
This test measures the total number of white blood cells in your blood and breaks down the types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) to help assess immune function and potential infections.
["Your immune system’s health and response to illness can be evaluated with this simple blood test."]
Key facts at a glance
- LOINC
- 57913-6
- Short code
- White Bean IgE/IgE total %
- Synonyms
- White Bean IgE/IgE total %
- 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
Why This Test Is Done
Doctors order a WBC differential when they suspect infections (like bacterial or viral), inflammation, autoimmune conditions, or other immune-related issues. It can also help monitor chronic diseases, such as leukemia or certain allergies, by tracking changes in white blood cell types over time.
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.
What the Results Mean
A high total WBC count may indicate infection, inflammation, or stress, while a low count could signal immune suppression. Changes in individual cell types (e.g., high eosinophils) might suggest allergies, parasites, or other conditions. Your doctor will interpret results in the context of your symptoms and medical history.
Common Conditions Monitored
This test helps diagnose or manage conditions like chronic infections, autoimmune diseases (e.g., lupus), certain cancers (e.g., lymphoma), and reactions to medications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
WBC differential results help pinpoint whether an infection is viral (often linked to lymphocytes) or bacterial (often linked to neutrophils). Elevated eosinophils may signal allergies or parasitic infections, while low lymphocyte counts could indicate HIV or other immune deficiencies. Doctors use these findings to tailor treatments, such as antibiotics or immune-modulating therapies.
Short name
WBC Differential
Frequently asked questions
What causes a high white blood cell count?
What does a low white blood cell count mean?
How often should I get this test?
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