Serum Immunoglobulin G (IgG) Level
This test measures the amount of Immunoglobulin G (IgG) in your blood, a type of antibody that helps fight infections and supports immune function.
["IgG helps protect your body against diseases and supports long-term immunity."]
Key facts at a glance
- LOINC
- 63379-2
- Short code
- dsDNA IgG Ser Ql
- Synonyms
- dsDNA IgG 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
- 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 Might Be Ordered
Your healthcare provider may order this test to evaluate your immune system, check for infections, assess immune deficiencies, or monitor conditions like autoimmune diseases, chronic infections, or certain cancers. It can also help diagnose or monitor diseases such as HIV, hepatitis, or other immune-related disorders.
What to Expect Before the Test
No special preparation is usually needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on blood thinners, let your provider know before the test.
What the Results Mean
Results can vary based on your health, age, and other factors. Low IgG levels may suggest an immune system issue, while very high levels could indicate certain infections, inflammation, or autoimmune conditions. Your provider will interpret results in the context of your overall health.
Common Conditions Monitored
IgG levels are often checked in people with suspected immune disorders, chronic illnesses, or those who have had organ transplants to ensure their immune system is functioning properly.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG is the most abundant antibody in your blood and plays a critical role in defending against bacteria and viruses. Low IgG levels may indicate a weakened immune response, increasing susceptibility to infections. High IgG levels can sometimes signal chronic inflammation, immune system activation, or certain medical conditions like multiple myeloma or severe infections.
Short name
IgG Level
Frequently asked questions
When Might I Need This Test?
What Are Normal IgG Levels?
Can Diet or Supplements Affect IgG Levels?
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