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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 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
74404-5
Short code
Eosinophil # BldCo
Synonyms
Eosinophil # BldCo
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Might Be Ordered

Your healthcare provider may order this test to check for conditions like allergies, asthma, parasitic infections, or certain types of cancer. It can also help monitor treatment responses or diagnose unexplained symptoms such as persistent itching, skin rashes, or digestive issues.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into a vein (usually in your arm) to draw blood. The process is quick and typically painless. If you’re nervous, let your healthcare provider know—they can offer options to make it more comfortable.

What the Results Mean

Results are reported as the absolute number of eosinophils per microliter (µL) of blood. High levels may indicate allergies, infections, or inflammatory conditions, while very low levels could suggest immune system issues or certain medications. Your provider will interpret results in the context of your health history.

Common Conditions Linked to Eosinophil Levels

Elevated eosinophil counts are often seen in conditions like allergic reactions, asthma, parasitic infections, or certain autoimmune diseases. Low levels may be associated with conditions affecting immune function or chronic illnesses like HIV. Always discuss your results with your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Eosinophils play a key role in defending against parasites, regulating immune responses, and managing inflammation. They release chemicals that can contribute to allergic reactions or tissue damage in some cases. High or low levels 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?
Elevated eosinophils can result from allergies, asthma, parasitic infections, certain cancers (like lymphoma), or inflammatory conditions. Chronic stress, certain medications, or autoimmune diseases may also play a role. Your doctor will consider your symptoms and medical history to determine the cause.
Can I lower my eosinophil count naturally?
While you can’t directly control eosinophil levels, managing allergies (e.g., avoiding triggers), treating infections, and maintaining a balanced diet may help. Some over-the-counter antihistamines or anti-inflammatory foods (like omega-3s) might support immune balance, but always consult your doctor before making changes.
Do I need to repeat this test if my levels are abnormal?
Yes, your doctor may recommend retesting to monitor changes over time or to investigate further causes. Additional tests (like allergy skin tests or imaging) might be needed to pinpoint the issue. Follow your provider’s guidance for follow-up steps.
  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