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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 certain infections and respond to allergies or inflammation.

Quick summary

["Eosinophils help protect your body from harmful substances and infections."]

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

Key facts at a glance

LOINC
71679-5
Short code
Eosinophil NFr.DF Bld Auto
Synonyms
Eosinophil NFr.DF Bld Auto
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
automated-count
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for conditions like allergies, asthma, parasitic infections, or certain types of cancer. High levels might suggest allergies, asthma, or other inflammatory or infectious processes, while low levels could indicate immune system issues or certain blood disorders.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a blood sample. The process is quick and usually painless.

What the Results Mean

Results are typically reported as the number of eosinophils per microliter (µL) of blood. While reference ranges vary by lab, elevated counts may signal allergic reactions, infections, or inflammatory conditions. Always discuss your results with your healthcare provider.

Common Conditions Linked to Eosinophil Levels

High eosinophil counts may be linked to allergies, asthma, parasitic infections, certain cancers (like lymphoma or leukemia), or autoimmune diseases. Low levels might suggest immune deficiencies or other blood disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Eosinophil Blood Test

Frequently asked questions

What causes eosinophil levels to rise?
Elevated eosinophil counts can result from allergies, asthma, parasitic infections, certain cancers, or inflammatory conditions. Stress, certain medications, or other immune responses may also play a role.
What should I do if my eosinophil test results are abnormal?
If your results are outside the expected range, your doctor will review them with you and may recommend additional tests or treatments based on your symptoms and medical history.
Can diet or lifestyle affect eosinophil counts?
While diet and lifestyle factors may influence overall immune function, they don’t directly affect eosinophil counts in blood tests. Your doctor will focus on symptoms and other health factors when 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