return to numerical index

return to index page


Test Directory -  5-H.I.A.A


Urinary 5HIAA, 5-Hydroxyindoleacetic acid

Clinical Indications

Investigation of suspected carcinoid syndrome

Request Form

Combined Pathology blood form (yellow/black)


Referral test: Analysed by Biochemistry, Broomfield Hospital.

Patient Preparation


None required

Specific Criteria


Turnaround Time

3 Weeks


24 hour urine collection into acid preservative


Acidified 24 hour urine container available from phlebotomy department at Basildon Hospital.

Patient Preparation and Collection

Patients should avoid serotonin-rich foods which can interfere with the assay (Bananas, pineapples, kiwi fruit, nuts and avocados.) All drugs should be recorded on request form. A patient information leaflet is available.

Lab. Handling

Record 24hr volume, aliquot and store at 4C

Causes for Rejection

Unlabelled urine bottle, incomplete 24 hour collection.

Reference Range

Less than 31 umol/24 hours.



Diet and drugs may affect results: levels >200 umol/24hrs suggest carcinoid.

Lab. Handling

Processing: Record the total urine and pH (a value of up to 6 is acceptable on acidified urines) in the 24 hour urine book, aliquot and store at 4C in separating fridge (CB39), referral rack.
:  U5H and send in Broomfield bag or BPRO and track at -20C in separating freezer (CB40).

 Version 1.0 / July 2014                                                                                                           Approved by: Consultant Biochemist