Serum or plasma immunoglobulin G (IgG) concentration

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like frequent infections, unusually slow healing of wounds, or if you’re being evaluated for conditions like immunodeficiency or autoimmune diseases. It may also be checked before certain treatments or vaccinations to ensure your immune system is strong enough.

What to Expect During the Test

A small blood sample is taken from a vein, usually in your arm. You may feel a slight pinch, but it’s quick and not painful. The sample is sent to a lab for analysis. No special preparation is needed, but let your provider know about any medications or supplements you’re taking.

Possible Results and Next Steps

Results are compared to a general reference range for healthy adults. Low IgG levels may indicate immune system issues, while very high levels might suggest conditions like multiple myeloma or chronic infections. Your provider will discuss results and next steps with you, which could include further testing or adjustments to treatment.

Common Conditions Affecting IgG Levels

IgG levels can drop due to conditions like Common Variable Immunodeficiency (CVID), HIV/AIDS, or certain cancers. They may rise in cases of chronic infections, autoimmune diseases, or certain blood disorders. Always discuss symptoms and test results with your healthcare team.