Immunoglobulin G (IgG)
Immunoglobulin G (IgG) is the most abundant antibody in your blood and provides long-lasting protection against infections. This test measures the total IgG level.
Because IgG reflects your longer-term immune memory and overall antibody defenses, making it useful when evaluating recurrent infections, immune deficiencies, or certain chronic conditions. It can also give context in autoimmune and inflammatory disorders. Measuring total IgG helps a clinician assess how well this part of your immune system is working.
A higher-than-normal IgG can be associated with chronic infections, chronic inflammation, liver conditions, or certain immune and blood disorders. Because the causes are broad, an elevated IgG usually leads your clinician to consider your symptoms and additional testing rather than pointing to one diagnosis.
A low IgG can suggest an immune deficiency that may leave you more prone to infections, or it can result from certain conditions or medications. Whether it needs action depends on your history and infection pattern, which your clinician evaluates.
A result within your lab's reference range is typical. Any high or low result should be interpreted by your clinician in light of your infection history and overall health.
Sources
- Immunoglobulins (IgA, IgG, IgM) Blood Test · MedlinePlus
- Immunoglobulins Blood Test · Cleveland Clinic
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.