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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, in your blood. Eosinophils help fight certain infections and respond to allergies and inflammation.

Quick summary

["Eosinophils help your body fight parasites and allergies, but high levels may signal underlying conditions."]

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

Key facts at a glance

LOINC
68398-7
Short code
Eosinophil # Pcar Manual
Synonyms
Eosinophil # Pcar 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 recommend this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained allergies. It could also be used to monitor conditions like parasitic infections, certain cancers, or reactions to medications.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm, and a few drops of blood will be drawn into a test tube or vial. The blood is then examined under a microscope to count eosinophils.

What the Results Mean

Eosinophil counts vary by age and health. High levels (above normal) may indicate allergies, infections, or conditions like asthma, certain cancers, or autoimmune diseases. Low levels may suggest immune suppression or other health issues.

Common Conditions Linked to Eosinophil Levels

Elevated eosinophils are often seen in allergic reactions, parasitic infections, certain lung diseases (like asthma or eosinophilic pneumonia), or conditions like hypereosinophilic syndrome. Low eosinophils may occur with stress, infections, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Eosinophil blood test

Frequently asked questions

How often will I need this test?
Your doctor will determine how often you need this test based on your symptoms, medical history, and treatment plan. Some patients may need it once, while others may require follow-ups over months or years.
What are normal eosinophil levels?
Normal ranges can vary by lab and age. Typically, healthy adults have between 0% and 7% eosinophils in their blood, but these numbers can shift with health changes.
Can lifestyle changes affect eosinophil levels?
Yes, stress, diet, and certain medications (like steroids) can influence eosinophil counts. Avoiding allergens or managing stress may help stabilize levels, but consult your doctor before making changes.
  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