Total IgG Immunoglobulin (Serum)
This test measures the amount of Immunoglobulin G (IgG) in your blood. IgG is the most common type of antibody and plays a key role in protecting your body from infections.
["IgG helps fight bacteria and viruses, ensuring long-term immunity."]
Key facts at a glance
- LOINC
- 110116-1
- Short code
- tTG IgA Msmt Ser
- Synonyms
- tTG IgA Msmt Ser
- 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 check for low or high levels of IgG, which can happen due to immune system issues, certain medical conditions, or after treatments like chemotherapy. It can also help diagnose or monitor conditions like autoimmune diseases, infections, or immune deficiencies.
What to Expect Before the Test
You can usually have this blood test done at a clinic, hospital, or lab. No special preparation is needed, but you may be asked to fast for a few hours before the test if it’s part of a larger panel. A small needle will be used to draw blood from your arm.
What the Results Mean
IgG levels can vary based on age, overall health, and medical conditions. Your results will be compared to standard ranges provided by your lab. Low IgG levels may indicate a weakened immune system, while very high levels might suggest certain immune disorders or chronic infections.
Common Conditions Affecting IgG Levels
Conditions like HIV/AIDS, certain autoimmune diseases (e.g., lupus), chronic infections, or treatments for cancer (like chemotherapy) can affect IgG levels. Children with immune deficiencies or those born with low IgG may also need monitoring.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG levels are critical for diagnosing and managing immune-related disorders. Low IgG can lead to recurrent infections, while elevated IgG may signal chronic inflammation or immune system activation. Regular monitoring helps manage these conditions effectively.
Short name
IgG Level
Frequently asked questions
How long does it take to get IgG test results?
What causes IgG levels to be low?
Can IgG levels change over time?
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