Experiencing recurrent infections, want comprehensive immune system assessment, or need evaluation of your long-term immunity and immune strength?
The Immunoglobulin G (IgG) test measures the most common type of antibody in the blood. IgG plays a key role in defending against bacterial and viral infections and provides long-term immunity after exposure or vaccination. Abnormal IgG levels can indicate immune deficiencies, chronic infections, autoimmune conditions, or certain allergies. This test is often used to assess immune system health, investigate recurrent infections, and monitor immune-related disorders.
You will be emailed a referral to take to your local collection centre. If you ever have any questions, we're here to help.
Think of the Immunoglobulin G (IgG) test as checking your immune system's memory bank. IgG antibodies are like your body's security guards that remember every infection or vaccination you've encountered, staying on patrol in your bloodstream to provide long-lasting protection. These antibodies are your most abundant defenders, making up the backbone of your long-term immunity and even protecting newborns by crossing from mother to baby during pregnancy.
This test reveals whether your immune system has the right amount of these protective antibodies to keep you healthy. Low IgG levels might explain why you're getting sick frequently, as it could signal that your immune system isn't producing enough defenders to fight off infections effectively. On the flip side, unusually high levels might indicate your body is working overtime to battle a chronic infection or dealing with an autoimmune condition where your immune system is overactive. Understanding your IgG levels helps determine if recurrent illnesses are due to immune deficiency and whether you might benefit from treatments to boost your body's natural defenses.
Reviewed by Dr. Vu Tran Bloody Good’s Chief Medical Officer
You may benefit from the Immunoglobulin G (IgG) Blood Test
Essential for individuals with recurrent infections, suspected immune deficiency, chronic illness affecting immunity, or anyone needing comprehensive immune function evaluation.
Frequent infections (more than 4 colds per year)
Infections that are severe or long-lasting
Slow healing of cuts or wounds
Chronic fatigue possibly related to infection
How to prepare
No special preparation required. Inform healthcare provider of recent infections, vaccinations, or medications that might affect immune function, as these can influence IgG levels and interpretation.
Understanding results
Results show IgG levels compared to age-appropriate normal ranges. Low levels may indicate immune deficiency, while elevated levels may suggest chronic infection, inflammation, or autoimmune conditions.
After the test
Address abnormal IgG levels through comprehensive immune evaluation, treatment of underlying conditions, immune support measures, or immunoglobulin replacement therapy if deficiency is confirmed. Work with immunologists for specialized care.
Frequently Asked Questions
Low IgG typically indicates immune deficiency, which can be primary (genetic) or secondary (due to medications, illness, or other factors), potentially increasing susceptibility to infections and requiring further evaluation.
Elevated IgG may indicate chronic infection, autoimmune disease, liver disease, or certain blood disorders, requiring clinical correlation and additional testing for proper diagnosis.
IgG provides long-term immunity and is the most abundant antibody, while IgM indicates recent infection and IgA protects mucosal surfaces - each serves different immune functions.
Yes, IgG levels can change due to infections, vaccinations, medications, aging, or underlying health conditions, which is why monitoring may be needed in certain situations.
IgG deficiency is a condition where IgG levels are below normal, potentially causing recurrent infections and may require treatment with immunoglobulin replacement therapy or other immune support measures.
Treatment may include immunoglobulin replacement therapy, prophylactic antibiotics, lifestyle modifications to reduce infection risk, and management of underlying conditions affecting immune function.
You will be emailed a referral to take to your local collection centre. If you ever have any questions, we're here to help.
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