Total Serum Immunoglobulin G (IgG) Level
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 helps fight infections and supports immune function by identifying and neutralizing harmful substances."]
Key facts at a glance
- LOINC
- 110124-5
- Short code
- T canis IgM Msmt Ser
- Synonyms
- T canis IgM 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
What IgG Does in Your Body
IgG is the most common type of antibody in your blood. It plays a key role in defending against bacteria and viruses, helping your immune system remember past infections to provide faster protection if you encounter the same pathogen again. It also helps neutralize toxins and foreign substances, contributing to overall immune defense.
Why Your Doctor Might Order This Test
Your doctor may order an IgG test to check for immune system function, diagnose conditions like immunodeficiency, or monitor treatment responses in diseases such as HIV, lupus, or certain autoimmune disorders. It can also help evaluate immune responses in newborns or individuals with chronic infections.
When You Might Need This Test
You might need this test if you have symptoms like frequent infections, unexplained fatigue, recurrent ear or sinus infections, or if you’re being treated for an immune-related condition. Doctors may also order it as part of a routine checkup for certain high-risk groups, such as newborns or individuals with weakened immune systems.
What to Expect During the Test
A simple blood draw is used to collect a serum sample. You’ll lie down or sit comfortably while a healthcare professional inserts a small needle into your arm. The blood is then sent to a lab for analysis. The process usually takes a few minutes, and you may feel slight discomfort or bruising afterward.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance of IgG Levels
Short name
IgG Level
Frequently asked questions
How long does it take to get the results of this test?
What do low IgG levels mean?
Can high IgG levels be harmful?
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