Eosinophil count (qualitative manual differential blood smear)
This test evaluates the presence and proportion of eosinophils—a type of white blood cell—in your blood, using a manual microscopic examination of a blood smear. It helps identify conditions where eosinophils may be elevated.
["Eosinophils can signal allergic reactions, infections, or inflammatory conditions; this test provides a qualitative snapshot of their role in your health."]
Key facts at a glance
- LOINC
- 57391-5
- Short code
- Eosinophil NFr Snv Manual
- Synonyms
- Eosinophil NFr Snv Manual
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained allergic reactions. It’s also used to monitor conditions like parasitic infections, certain cancers, or autoimmune disorders where eosinophil levels may change.
How the Test Works
A small blood sample is drawn and spread thinly on a glass slide. A trained lab technician examines the slide under a microscope, counting and identifying different types of white blood cells, including eosinophils, to determine their relative presence.
What to Expect Before the Test
No special preparation is needed. You may have a slight bruise or soreness at the injection site, but this is normal. Avoid heavy exercise or aspirin 24 hours before the test if your provider advises it.
What to Expect After the Test
Results are typically available within 1–3 business days. You’ll receive a qualitative report indicating whether eosinophils are present above or below expected levels, not a specific numeric count.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated eosinophils may indicate allergic reactions, parasitic infections, certain lung diseases (e.g., asthma), or autoimmune conditions. Low or absent eosinophils could suggest immune suppression or other systemic issues. This test supports diagnosis but isn’t definitive alone—additional tests may be needed.
Short name
Eosinophil count (qualitative)
Frequently asked questions
How long does it take to get results?
Can I eat or drink before this test?
Is there any risk or discomfort?
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