Total Immunoglobulin E (IgE) Level
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.
["IgE helps identify allergies or immune reactions to certain substances."]
Key facts at a glance
- LOINC
- 42863-1
- Short code
- CEDRIGE
- Synonyms
- Cedar IgE/IgE total %
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Immunoassay (Fluorescent Enzyme Immunoassay or Chemiluminescent Immunoassay)
- CPT
- 86003
- SNOMED
- 395147008
- Specimen volume
- 1-2 mL of serum
- Stability
- Room temperature: 8 hours. Refrigerated (2-8°C): 7 days. Frozen (-20°C or below): 1 month. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 300
- Icterus max
- 40
- TAT
- 24–72 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, dust mites, or certain foods), it can produce higher levels of IgE to help defend against it. This test helps doctors understand if you have an allergic reaction or an overactive immune response.
Why Might You Need This Test?
Doctors may order this test if you have symptoms like sneezing, itching, hives, or trouble breathing that suggest allergies. It can also help diagnose conditions like asthma, eczema, or certain types of immune disorders.
How Is the Test Done?
A small blood sample is taken from a vein in your arm. The blood is then sent to a lab for testing. The test measures the total amount of IgE in your blood, regardless of the specific allergen causing the reaction.
What Do the Results Mean?
Results are not given in a specific range because IgE levels can vary widely depending on age, health, and exposure to allergens. High IgE levels may indicate allergies or immune-related conditions, while normal or low levels may suggest fewer allergic reactions.
Reference range
Cedar IgE: Negative (<0.35 kU/L). Total IgE: 0-100 IU/mL for adults. Reference ranges may vary by laboratory methodology and patient age.N/A
No special patient preparation required. Specimen should be collected prior to administration of antihistamines, corticosteroids, or other immunosuppressive medications when clinically feasible, as these may affect results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgE Total
Frequently asked questions
How often do I need this test?
Can IgE levels change over time?
What if my IgE levels are high?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 15, 2026. · Read our editorial policy