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Eosinophil count in serum/plasma (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 play a role in allergic reactions.

Quick summary

["Eosinophils help your body defend against certain infections and allergies, and this test helps doctors monitor their levels."]

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

Key facts at a glance

LOINC
22288-5
Short code
E histolyt IgG Ser-aCnc
Synonyms
E histolyt IgG Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Might This Test Be Done?

Your healthcare provider may order this test to investigate symptoms such as persistent coughing, wheezing, skin rashes, or unexplained weight loss. It can also help diagnose conditions like asthma, allergies, parasitic infections, or certain types of cancer.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw at a clinic, hospital, or your doctor’s office. The process is quick and usually painless.

What the Test Results Mean

Elevated eosinophil counts may indicate allergies, infections, or inflammatory conditions. Lower-than-normal levels might suggest certain immune disorders or blood disorders. Your results will be interpreted by your healthcare provider in the context of your overall health.

Common Conditions Linked to Eosinophil Counts

High eosinophil counts can be associated with conditions like asthma, eosinophilic esophagitis, certain types of cancer (e.g., lymphoma), or parasitic infections. Low levels may be linked to conditions like aplastic anemia or certain autoimmune diseases.

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-than-normal eosinophil counts can result from allergies, asthma, parasitic infections, certain cancers, or inflammatory conditions. Your doctor may also consider medications you’re taking, recent infections, or other underlying health issues.
Can I lower my eosinophil count naturally?
While you can’t directly control eosinophil levels through diet alone, managing allergies (e.g., avoiding triggers), treating infections, and following your doctor’s advice for managing conditions like asthma can help. Avoiding certain medications (e.g., NSAIDs) that may affect white blood cells is also recommended.
How often should I get this test?
Your doctor will determine how often you need this test based on your symptoms, medical history, and treatment plan. Regular follow-ups may be scheduled if you have ongoing conditions like allergies or asthma.
  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