5-Hydroxyindoleacetic Acid

5-Hydroxyindoleacetic Acid

Other names: 5-HIAA, HIAA, 5-hydroxyindole acetic acid, Serotonin metabolite
Specimen: 24-Hour Urine



Your 5-Hydroxyindoleacetic Acid is

The normal range is less than or equal to 6 milligrams per 24 hours (mg/24h).

5-Hydroxyindoleacetic acid is the main metabolite of serotonin in the human body. In chemical analysis of urine samples, 5-HIAA is used to determine the body's levels of serotonin. 5-HIAA is tested by 24-hour urine samples combined with an acidic additive to maintain pH below 3. Certain foods and drugs are known to interfere with the measurement. 5-HIAA levels can vary depending on other complications, including tumors, renal malfunction, and small bowel resection.
This test measures the level of 5-HIAA in the urine. It is often done to detect tumors in the digestive tract (carcinoid tumors) and to track a patient's condition.

The urine test may also be used to diagnose mastocytosis and endocrine tumors.