Supporting the

Neuroendocrine Cancer Community

5-HIAA 24 hour Urine Collection Test

Jun 30, 2021

5-HIAA 24 hour Urine Collection Test

Urinary 5-HIAA (5-hydroxyindoleacetic acid) 5-HIAA is a breakdown product of a hormone called serotonin which is excreted from the body in urine. It is an indirect way to measure how much serotonin is in the body. Serotonin can be released by Neuroendocrine Cancer cells – especially in those with Carcinoid Syndrome.


Please note – we are unable to provide a complete list of the foods and medications to avoid when under going the 24hr 5H1AA Urine test. Each laboratory and / or hospital institution has their own specific requirements and protocols. These can often, also, be patient specific – especially in regards to medications. You should be issued with an instruction sheet when asked to carry out this test, but if this was not given to you or you are in any doubt, please contact your CNS or healthcare team (or Laboratory, if known).