Total Immunoglobulin G (IgG) in Serum

Why This Test Is Done

Your healthcare provider may order this test to evaluate your immune system, diagnose conditions like immunodeficiency, or monitor treatment for diseases such as HIV, lupus, or certain infections. It can also be used to check for immune responses after vaccination or during pregnancy to ensure proper antibody levels.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm to draw blood. This is usually quick and painless, though some people feel slight discomfort. If you have a hard time getting blood, your provider may suggest a different vein or use a tourniquet to help.

What the Test Results Mean

Results may be compared to standard ranges to determine if your IgG levels are low, normal, or high. Low levels might suggest an immune disorder, while high levels could indicate chronic infections, autoimmune diseases, or other conditions. Your provider will discuss these results with you in detail.

Common Conditions Monitored

IgG levels are often checked in people with conditions like HIV/AIDS, certain autoimmune diseases (e.g., systemic lupus erythematosus), chronic infections, or those who have had organ transplants. It can also be used to monitor immune recovery post-vaccination or in newborns to check for maternal antibody transfer.