Quantitative Immunoassay for Immunoglobulin G (IgG) in Serum or Plasma
This test measures the amount of Immunoglobulin G (IgG), a type of antibody in your blood. IgG helps protect your body from infections and is important for long-term immunity.
["IgG levels help assess immune function and diagnose conditions like infections, immune deficiencies, or certain autoimmune diseases."]
Key facts at a glance
- LOINC
- 100400-1
- Short code
- Quail meat IgG Qn
- Synonyms
- Quail meat IgG Qn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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 Is Done
Your healthcare provider may order this test to evaluate your immune system. Common reasons include diagnosing or monitoring conditions such as chronic infections, immune disorders, or determining if you have enough antibodies after vaccination or illness. It may also be used to check for signs of immune system overactivity or deficiency.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re on blood thinners, let your provider know before the test.
What the Test Results Mean
IgG levels can vary based on age, overall health, and medical conditions. While reference ranges exist, they can differ by lab. High IgG levels might suggest chronic infections, certain cancers, or immune system overactivity. Low IgG levels could indicate immune deficiencies or conditions like HIV or severe malnutrition.
Common Conditions Linked to IgG Levels
Abnormally high IgG levels may be linked to chronic infections (e.g., tuberculosis), certain cancers (e.g., multiple myeloma), or autoimmune diseases (e.g., lupus). Low IgG levels can be associated with primary immune deficiencies, HIV/AIDS, or conditions that impair nutrient absorption.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG levels are critical for diagnosing and managing immune-related disorders. They help guide treatment decisions, such as adjusting medication for immune deficiencies or monitoring response to infections. Persistently abnormal levels may prompt further testing to identify underlying causes.
Short name
IgG Level
Frequently asked questions
How long does it take to get my IgG test results?
Can I eat or drink before this test?
What if my IgG levels are outside the normal range?
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 16, 2026. · Read our editorial policy