5-Hydroxyindoleacetic Acid (5-HIAA)

5-Hydroxyindoleacetic Acid (5-HIAA) is a chemical that results from the breakdown of serotonin, a neurotransmitter involved in regulating mood, digestion, and sleep. Measuring 5-HIAA levels in urine helps doctors diagnose and monitor certain health conditions, especially carcinoid tumors, which are rare cancers that produce excess serotonin. Elevated or abnormal 5-HIAA levels can indicate the presence of such tumors or other related disorders. The test provides important insights into serotonin metabolism and helps guide appropriate treatment strategies.