Immunoglobulin G (IgG) mass concentration in serum/plasma
This test measures the amount of Immunoglobulin G (IgG), a type of antibody found in your blood. IgG helps protect your body from infections by fighting bacteria and viruses.
["IgG helps fight infections and is a key part of your immune system."]
Key facts at a glance
- LOINC
- 63170-5
- Short code
- H interseminatum IgG-mCnc
- Synonyms
- H interseminatum IgG-mCnc
- 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 doctor may order this test to check if your immune system is working properly. It can help diagnose or monitor conditions like low immunity, certain infections, or immune system disorders. It may also be used to evaluate responses to treatments or vaccinations.
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 nervous, let your healthcare provider know so they can help make it more comfortable.
What the Test Results Mean
Results are compared to a general range of what’s considered normal for IgG levels in blood. While reference ranges can vary slightly by lab, very low or very high levels may signal potential health concerns that need further evaluation.
Common Conditions Monitored
IgG levels are often checked in people with weakened immune systems, those recovering from infections, or those receiving treatments like chemotherapy. It can also be used to assess immune responses after vaccines.
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 long-term immunity. Low IgG levels may indicate immune deficiencies, chronic infections, or malabsorption issues, while very high levels can sometimes be linked to autoimmune conditions or certain cancers. Your doctor will interpret results in the context of your overall health.
Short name
IgG Level
Frequently asked questions
What causes IgG levels to be checked?
How long does it take to get test results?
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