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Immunoglobulin E (IgE) concentration in serum or plasma

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.

Quick summary

["IgE helps identify allergic reactions and certain immune conditions."]

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

Key facts at a glance

LOINC
44594-0
Short code
IgE Ser Ql
Synonyms
IgE Ser Ql
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

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like sneezing, itching, hives, or asthma, which could suggest an allergy. It may also be used to diagnose conditions like allergic rhinitis, asthma, or atopic dermatitis. In some cases, it helps evaluate immune system disorders or reactions to infections.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm. If you’re taking blood thinner medications, let your doctor know before the test.

What the Test Results Mean

IgE levels can vary widely depending on age, overall health, and exposure to allergens. High levels may indicate allergies or immune-related conditions, while very low levels might suggest a weakened immune response. Your doctor will interpret results in the context of your symptoms and medical history.

Common Uses and Conditions

IgE testing is often used to confirm allergies to foods, pollen, pets, or other substances. It can also help diagnose conditions like chronic urticaria (hives), eosinophilic disorders, or certain parasitic infections.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgE Level

Frequently asked questions

What Are My Next Steps If My IgE Level Is Abnormal?
If your IgE level is elevated, your doctor may recommend allergy testing (like skin prick tests or blood allergy panels) to identify specific triggers. If levels are low, further evaluation may focus on immune function or other underlying conditions. Follow-up depends on your symptoms and doctor’s recommendations.
How Often Should I Get This Test?
IgE testing is typically done once or twice a year if monitoring allergies or immune conditions. Your doctor will determine how often based on your treatment plan and symptoms. Avoid unnecessary retests unless advised by a healthcare provider.
Can I Take Anything Before the Test?
No special preparations are needed, but inform your doctor about any medications (especially blood thinners) or recent illnesses that might affect results.
  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