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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 caused by parasites and certain allergens.

Quick summary

["Eosinophils help your body defend against harmful substances and infections."]

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

Key facts at a glance

LOINC
20816-5
Short code
E coli K88 Islt Ql Aggl
Synonyms
E coli K88 Islt Ql Aggl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
aggl
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 Is This Test Done?

Doctors may order an eosinophil count to diagnose or monitor conditions such as allergies, asthma, parasitic infections, certain types of cancer (like leukemia), or autoimmune diseases. It can also help evaluate symptoms like persistent itching, skin rashes, or unexplained fevers.

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 is quick and typically painless. If you’re nervous, let your healthcare provider know so they can provide reassurance or additional support.

What the Results Mean

Eosinophil counts can vary based on health, diet, and recent infections. High levels may indicate allergies, infections, or inflammatory conditions, while low levels might suggest immune suppression or certain blood disorders. Your doctor will interpret the results in the context of your overall health and symptoms.

Common Conditions Linked to Eosinophil Counts

Elevated eosinophil counts are often seen in conditions like allergic reactions, asthma, parasitic infections, and certain cancers. Lower-than-normal counts may be linked to conditions like HIV/AIDS, chemotherapy, or other immune system disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Absolute Eosinophil Count

Frequently asked questions

What causes my eosinophil count to be higher than usual?
Higher eosinophil counts can result from allergies, asthma, parasitic infections, certain cancers (like Hodgkin lymphoma), or autoimmune diseases. Stress, certain medications, or recent infections may also temporarily raise levels. If you notice persistent symptoms like itching, skin rashes, or unexplained weight loss, discuss your results with your doctor.
Can diet or supplements affect my eosinophil count?
Diet alone typically does not significantly alter eosinophil counts, but certain supplements (like fish oil or probiotics) or medications (e.g., steroids, antihistamines) may influence immune responses indirectly. Always check with your healthcare provider before starting new supplements or medications, especially if you have a known condition linked to eosinophil levels.
How often should I get this test?
The frequency depends on your health condition and treatment plan. If you have a chronic condition like asthma or allergies, your doctor may recommend regular monitoring. For one-time evaluations (e.g., diagnosing an infection), this test may be done only once or twice. Follow your healthcare provider’s guidance.
  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