Total IgG Immunoglobulin (Serum)
This test measures the amount of Immunoglobulin G (IgG), the most common type of antibody in your blood. IgG helps fight infections and is important for long-term immunity.
["IgG supports your immune system’s defense against bacteria and viruses."]
Key facts at a glance
- LOINC
- 53026-1
- Short code
- tTG IgG Ser Ql
- Synonyms
- tTG 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
What Does IgG Serve in Your Body?
IgG antibodies are produced by your immune system to protect against infections. They are found in the blood and provide long-term immunity by helping your body remember past infections. IgG is also the primary antibody passed from mother to baby during pregnancy to provide newborns with initial immunity.
Why Might Your Doctor Order This Test?
Your doctor may check IgG levels if you have symptoms of an immune system disorder, such as frequent infections, unusual bleeding, or if you’re being treated for conditions like lupus, rheumatoid arthritis, or certain autoimmune diseases. It can also be part of monitoring for immune deficiencies or responses to treatments like chemotherapy.
Common Reasons for Testing
Tests for IgG are often done when diagnosing or managing conditions that affect antibody production, such as immunodeficiency diseases, infections, or certain cancers. It may also be checked in newborns to assess early immunity.
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 the process more comfortable.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG Level
Frequently asked questions
How low or high IgG levels might be interpreted depends on your overall health and medical history. Very low IgG levels can indicate a weakened immune system, while very high levels may suggest certain immune disorders or chronic infections. Your doctor will review your results in the context of your symptoms and other tests.
What happens if my IgG levels are abnormal?
Can diet or lifestyle 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