Leukocyte (White Blood Cell) Fraction Percentage by Differential Count
This test measures the percentage breakdown of different types of white blood cells in your blood, helping identify imbalances that may signal infections, inflammation, or other health concerns.
["Understanding your white blood cell types can help doctors diagnose and guide treatment for conditions like infections or immune disorders."]
Key facts at a glance
- LOINC
- 72104-3
- Short code
- Leuk FTperCT Pnl Bld/T
- Synonyms
- Leuk FTperCT Pnl Bld/T
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- 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 may order this test to evaluate symptoms such as frequent infections, unexplained fevers, fatigue, or signs of immune system dysfunction. It can also be part of routine blood work or monitoring for conditions like leukemia, autoimmune diseases, or chronic infections.
What to Expect Before the Test
No special preparation is needed. A simple blood draw from your arm is all that’s required. The test is typically done in a lab setting and results are usually available within a few days.
How the Test Works
A small sample of blood is taken and analyzed under a microscope to count and identify the different types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils). Each type is then expressed as a percentage of the total white blood cell count.
Possible Results and Interpretation
While specific percentages can vary based on health status, an abnormal differential may indicate an infection, allergy, or other underlying conditions. Your doctor will interpret results in the context of your overall health and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal percentages of white blood cells can point to specific health issues. For example, a high neutrophil count might suggest an infection, while a low lymphocyte count could indicate immune suppression. Doctors use these findings to tailor treatments, such as antibiotics for infections or immune-modulating therapies for autoimmune conditions.
Short name
White Blood Cell Differential Percentages
Frequently asked questions
What does a white blood cell differential test show?
How long does it take to get results from this test?
Can I eat or drink before 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