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Total Serum IgE (Immunoglobulin E) Level

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 plays a role in allergic reactions and responses to parasites.

Quick summary

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

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

Key facts at a glance

LOINC
61215-0
Short code
Giant Ragweed IgE/IgE total %
Synonyms
Giant Ragweed IgE/IgE total %
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 in response to allergens (substances like pollen, dust, or certain foods) or parasitic infections. While IgE is important for protecting against harmful invaders, high levels can trigger allergic reactions such as hives, asthma, or hay fever.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms of allergies (e.g., sneezing, itching, or skin rashes), asthma, eczema, or if you’ve been exposed to potential allergens. It can also help diagnose conditions like allergic rhinitis, atopic dermatitis, or certain parasitic infections.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm to draw blood. If you’re taking blood from your finger, it may sting briefly, but the procedure itself is quick.

What Happens During the Test?

A healthcare professional will collect a blood sample from a vein in your arm. The sample will be sent to a lab for analysis. Results are typically available within a few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated IgE levels often indicate allergies or allergic disorders, such as hay fever, asthma, or food allergies. Very high levels may also suggest parasitic infections or certain autoimmune conditions. Low IgE levels are less common but can sometimes be associated with rare immune deficiencies or certain infections.

Short name

IgE Total

Frequently asked questions

What Does My IgE Test Result Mean?
If your IgE level is higher than expected, it may suggest an allergic reaction or immune response. If it’s lower than expected, it may indicate a rare immune condition or infection. Your doctor will discuss the results with you and may recommend further testing if needed.
Can IgE Levels Change Over Time?
Yes, IgE levels can fluctuate depending on your health, exposure to allergens, or underlying conditions. If you’ve had recent changes in symptoms (like new allergies or worsening asthma), your doctor may retest IgE levels to monitor trends.
Does Diet or Medication Affect IgE Levels?
Some medications (like antihistamines) can temporarily lower IgE levels, but they don’t change the underlying cause. Dietary changes alone won’t alter IgE levels, but avoiding known allergens may help manage symptoms.
  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