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Eosinophil Count (Peripheral Blood)

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

This test measures the number of eosinophils, a type of white blood cell, in your blood. Eosinophils help fight infections and respond to allergies and inflammation.

Quick summary

["Eosinophils help your body defend against parasites and allergens; elevated levels may signal an infection, allergy, or other conditions."]

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

Key facts at a glance

LOINC
105112-7
Short code
Eosinophil NFr UrnS
Synonyms
Eosinophil NFr UrnS
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

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 allergic reactions, parasitic infections, or certain types of cancer.

What to Expect Before the Test

This is a simple blood draw, usually done in a doctor’s office or lab. You may feel a slight pinch, but it’s quick and doesn’t require special preparation.

What the Results Mean

Results are compared to a general reference range for healthy adults. High levels may indicate allergies, infections, or autoimmune disorders, while very low levels might suggest immune system issues or certain medications.

Common Conditions Linked to Results

Elevated eosinophils can be seen in conditions like asthma, hay fever, parasitic infections, or certain cancers (e.g., Hodgkin lymphoma). Low levels may occur with stress, certain medications, or immune deficiencies.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Elevated eosinophils often point to chronic inflammation, allergic reactions, or parasitic infections. They can also be associated with autoimmune diseases or certain cancers. Low eosinophil counts may suggest immune suppression, stress, or rare blood disorders.

Short name

Eosinophil Level

Frequently asked questions

What causes eosinophil levels to rise?
Elevated eosinophils can be triggered by allergies, asthma, parasitic infections, certain cancers, or autoimmune diseases. Stress, infections, or medications (like steroids) may also temporarily lower them.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up visit.
Can diet or lifestyle affect eosinophil counts?
While diet and lifestyle don’t directly change eosinophil levels, they can influence overall health. Managing allergies, infections, or stress may indirectly affect test results, but fasting isn’t required for this blood test.
  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