For which condition is the C3 test used?

The C3 test measures the level of complement component 3 (C3) in the blood, which is a protein that plays a crucial role in the body’s immune system and inflammation response. Elevated or decreased levels of C3 can indicate the presence of an underlying condition associated with inflammation or immune dysregulation.

When there is unexplained inflammation or edema in a patient, the C3 test can help in diagnosing conditions such as autoimmune diseases, infections, or other inflammatory disorders. Therefore, using the C3 test in the context of unexplained inflammation or edema is particularly relevant, making it the correct choice in this scenario.

On the other hand, while the C3 test may provide some insight into immune function, it is not routinely used to evaluate diabetes, test for hypertension, or assess liver function specifically. These conditions typically require more focused tests that directly relate to glucose metabolism, blood pressure, and liver enzymes, respectively.