Referred to Berkshire & Surrey Pathology Services, Frimley Park Hospital NHS Foundation Trust, Portsmouth Road, Frimley, Surrey GU16 7UJ

Alternative names, keywords

5-Hydroxyindoleacetic acid, 5HIAA

Samples required

24h urine collection - click here for printable instructions

24 hour urine collection in acidified container.

Patient must exclude the following foodstuffs and drugs for 48 hours before and during collection: avocados, bananas, kiwi fruit, pineapple, red plums, tomatoes, walnuts, alcohol, cough mixture and paracetamol.  Click here for printable list.

Test indications

Suspected carcinoid syndrome.

Reference range

< 47 µmol/24h

Note change to reference range from 1.6.2019 due to change of provider at referral laboratory.

Turnaround time

Referral lab quotes turnaround time of 10 working days, however additional time must be allowed for packing, dispatch and delivery of sample, and return and processing of results.


Biochemistry (Referrals)