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Eosinophil count (absolute)

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 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
5349-6
Short code
ENA Scl70 Ab Ser Ql ID
Synonyms
ENA Scl70 Ab Ser Ql ID
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-diffusion
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 recommend this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained allergies. It could also be used to check for conditions like parasitic infections, certain cancers, or autoimmune 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 blood. The process takes just a few minutes, and you may feel a brief pinch.

What the Results Mean

Results are usually reported as the number of eosinophils per microliter (µL) of blood. High levels may suggest allergies, infections, or other health issues, while very low levels might indicate immune system problems or certain medications.

Common Conditions Linked to Eosinophil Levels

Elevated eosinophil counts are often seen in allergic reactions, asthma, parasitic infections, or certain types of cancer (like Hodgkin lymphoma). Low levels may be linked to immune deficiencies or long-term steroid use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Eosinophils play a key role in defending against parasites, managing allergic responses, and responding to chronic inflammation. Abnormal counts can signal underlying health concerns that require further evaluation.

Short name

Eosinophil blood count

Frequently asked questions

What causes eosinophils to be high in my blood?
High eosinophil counts can result from allergies, asthma, parasitic infections, certain cancers, or autoimmune diseases. Your doctor will discuss symptoms and other tests to determine the cause.
How long does it take to get my test results?
Results are typically available within 1–3 business days, depending on your lab. Your doctor will contact you with the final report once it’s ready.
Can I eat or drink before this test?
No special diet is needed. You can eat and drink normally before the blood draw, but avoid smoking or heavy exercise right before testing.
  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