Preferred Sample Type

5 Hydroxy Indole Acetic Acid (5HIAA)

Suitable Specimen Types

  • 24 Hour Urine (Acid Collection)
24hr urine collection (3 mL urine required for assay)

Specimen Transport

Not applicable

Sample Processing in Laboratory

No special transport conditions apply

Turnaround Time

2 weeks

Sample Stability

Stored at 4oC

5 Hydroxy Indole Acetic Acid (5HIAA)

General Information

Measurement of urinary 5-hydroxy indole-3-acetic acid (5HIAA) output is used in the diagnosis and follow up of patients with carcinoid tumours. These tumours are found principally in the gastrointestinal tract, but may also occur in the respiratory and urogenital tracts. The "carcinoid syndrome" is attributable to carcinoid tumours of the mid-gut with liver metastases or primary tumours, such as ovarian carcinoids, with direct drainage into the circulation. The classical syndrome consists of attacks of skin flushing, diarrhoea and less frequently bronchoconstriction. Features of the disease, which may vary between patients, are thought to be mediated by a variety of tumour-produced secretory products including the monoamine 5 hydroxytryptamine (5HT). The 5HT produced is metabolised to 5HIAA and excreted in the urine.

Patient Preparation



None Given

Reference Range

5HIAA <50μmol/24h

5HIAA is affected by diet; levels can increase following ingestion of pineapples, bananas and some nuts.


  • EQA Scheme?: Yes
  • EQA Status:

    UKNEQAS for Urinary Catecholamines Scheme 

The laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital form part of the services provided by University Hospitals Birmingham and are UKAS (United Kingdom Accreditation Service) accredited to the ISO 15189:2012 standard. For a list of accredited tests and other information please visit the UKAS website using the following link:

  • Heartlands, Good Hope and Solihull Hospital pathology laboratories are a UKAS accredited medical laboratory No.8217
  • United Kingdom Health Security Agency laboratory is a UKAS accredited medical laboratory No.8213

Tests not appearing on the UKAS Schedule of Accreditation currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further test information, please visit the test database:

For further information contact Louise Fallon, Quality Manager, 0121 424 1235