Individual test · Labcorp 504510

5‐HIAA, Plasma

This test measures 5-HIAA in your blood, a waste product created when the body breaks down the hormone serotonin. It helps show whether symptoms like flushing, diarrhea, or wheezing are caused by tumors that release too much of this hormone. Doctors use these results to help identify or rule out neuroendocrine tumors, specifically carcinoid tumors. However, this test cannot locate a tumor or confirm a diagnosis by itself, as certain foods and medicines can also affect the levels.