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Serum IgE Immunoassay (Total Immunoglobulin E)

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

This test measures the amount of Immunoglobulin E (IgE) in your blood. IgE is a type of antibody that your immune system produces in response to allergens or other triggers.

Quick summary

["IgE levels help identify allergies or immune reactions."]

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

Key facts at a glance

LOINC
24511-8
Short code
West wheatgrass IgE Qn
Synonyms
West wheatgrass IgE Qn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

What Is Immunoglobulin E (IgE)?

IgE is a protein produced by your immune system that plays a key role in allergic reactions. When your body encounters an allergen (like pollen, pet dander, or certain foods), it may produce higher levels of IgE to help defend against it. While IgE is usually protective, elevated levels can indicate allergies or other immune conditions.

Why Might You Need This Test?

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

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is then sent to a lab where it is analyzed using an immunoassay method to measure IgE levels.

What Do Results Mean?

Results are reported in units of IgE per milliliter (IU/mL). Higher than normal levels may suggest allergies, while very low levels might indicate a weakened immune response to allergens.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated IgE levels are commonly associated with allergic disorders, such as hay fever, food allergies, or atopic dermatitis. They may also be linked to other conditions like parasitic infections or certain autoimmune diseases. Low IgE levels, however, are less commonly significant unless part of a broader evaluation for immune dysfunction.

Short name

IgE Level

Frequently asked questions

What causes elevated IgE levels?
Elevated IgE levels are most often linked to allergies, where your immune system overreacts to harmless substances. Other possible causes include chronic infections (like parasitic worms), certain autoimmune conditions, or allergic asthma.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will contact you once they are ready.
Can IgE levels change over time?
Yes, IgE levels can fluctuate based on exposure to allergens, immune responses, or underlying health conditions. Repeated testing may be needed if symptoms persist or worsen.
  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