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Serum Immunoglobulin E (IgE) concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of Immunoglobulin E (IgE) in your blood, a type of antibody linked to allergic reactions and certain immune responses.

Quick summary

["IgE helps identify allergies or immune system activity."]

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

Key facts at a glance

LOINC
77200-4
Short code
SI gene Mut Anl Bld/T
Synonyms
SI gene Mut Anl Bld/T
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
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

What Does IgE Measure?

IgE is produced by your immune system in response to allergens (like pollen, dust, or certain foods) or in chronic inflammatory conditions. High levels may suggest allergies, asthma, or other allergic disorders.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like sneezing, itching, skin rashes, or breathing difficulties that suggest allergies. It can also help diagnose conditions like allergic rhinitis, eczema, or certain parasitic infections.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate serum, which is tested for IgE levels using an immunoassay method.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications (especially blood thinners) or recent illnesses that might affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgE Level

Frequently asked questions

What causes elevated IgE levels?
Elevated IgE levels are commonly caused by allergies to environmental triggers (e.g., pollen, pet dander), certain foods, or medications. They can also be linked to chronic inflammatory conditions, parasitic infections, or autoimmune disorders. Stress or emotional factors may also play a role in some individuals.
Can IgE levels change over time?
Yes, IgE levels can fluctuate based on exposure to allergens, underlying health conditions, or treatments like allergy immunotherapy (allergy shots). For example, symptoms or IgE levels may improve with treatment or decrease after avoiding triggers.
Does this test diagnose asthma?
No, while high IgE levels can be associated with asthma, they are not definitive proof. Your doctor may use this test alongside other assessments (like spirometry or symptom history) to evaluate asthma risk or diagnosis.
  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