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Eosinophil count (manual differential blood cell count)

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

This test measures the number of eosinophils, a type of white blood cell involved in allergic reactions and fighting parasites. It’s often part of a complete blood count (CBC) to check for infections, allergies, or other conditions.

Quick summary

["Eosinophils help identify possible allergic responses or parasitic infections."]

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

Key facts at a glance

LOINC
11106-2
Short code
Eosinophil NFr Mar Manual
Synonyms
Eosinophil NFr Mar Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
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 Might Be Ordered

Your doctor may order this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained weight loss. It can also help diagnose conditions like parasitic infections, certain cancers, or allergic reactions that other tests might miss.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. The test is quick and usually done in a lab setting. If you’re on blood thinners, let your doctor know before the procedure.

What the Results Mean

Eosinophil counts can vary based on health, diet, and medications. High levels may suggest allergies, asthma, or infections, while very low levels could indicate immune disorders or certain medications. Your doctor will interpret results in the context of your overall health.

Common Conditions Linked to Eosinophil Levels

Elevated eosinophils are often seen in conditions like asthma, allergic reactions, parasitic infections, or certain autoimmune diseases. Low eosinophil counts may be linked to conditions like aplastic anemia or certain cancers, though this is less common.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Eosinophils Play a Key Role in Immune Responses

Short name

Eosinophil count

Frequently asked questions

What does a high eosinophil count mean?
A high eosinophil count may signal an ongoing allergic reaction, parasitic infection, or inflammatory condition like asthma. It can also appear in certain cancers or autoimmune diseases, so your doctor will review your symptoms and other test results to determine the cause.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab. If your doctor ordered this test as part of a routine CBC, results may be available sooner. Follow-up with your healthcare provider if you have questions.
Can diet or medications affect eosinophil counts?
Yes, certain medications (like steroids or blood pressure drugs) or dietary changes (e.g., high salt intake) can temporarily affect white blood cell counts. If you’re unsure about recent medications or dietary changes, discuss them with your doctor before interpreting results.
  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