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5-hydroxyindoleacetic acid (HIAA) test

Your doctor has requested that you have a 5-hydroxyindoleacetic acid (5-HIAA) test, which requires you to collect all urine that you pass over a 24-hour period.

Safety precautions—hydrochloric acid preservative

  • The bottle provided for the collection contains highly corrosive hydrochloric acid preservative.
  • If the acid comes into contact with your skin or clothing, wash the area thoroughly with water.
  • If poisoning occurs, consult a doctor or the Poison Information Centre (13 11 26).
  • Keep out of reach of children.

Dietary restrictions

For 3 days before the collection starts, you must avoid the following foods:

  • bananas
  • tomatoes
  • plums/plum jam
  • avocados
  • eggplant
  • pineapples/pineapple juice
  • walnuts.

Collecting your sample

It is important that the urine sample is completed over a 24-hour period. It is recommended that you start the collection process in the morning after you first rise. If you forget to use the bottle during the collection period, simply restart the collection. Contact the laboratory for advice if you cannot complete the collection for any reason.

  1. Label the collection bottle provided with your full name and date of birth.
  2. At the beginning of day one empty your bladder into the toilet and mark the time in the space provided on the collection bottle.
  3. Over the next 24 hours collect all of your urine into the bottle. Each time you add urine to the bottle, mix gently with the acid—avoid contact with the skin.
  4. The last collection should be as near as possible to the time of the first discarded specimen on day one, and should include the urine you pass first thing on day two. Make sure that the start and finish date and time are clearly marked on the bottle.
  5. Place the request slip into the biohazard bag and attach the bag to the collection bottle making sure not to cover the label.
  6. Keep the collection bottle in a cool place during the collection period—refrigerate if possible. Return it to the collection centre on the morning you finish the collection.

If you have any questions, please contact your preferred collection centre or your referring doctor.

Need more information?

5-hydroxyindoleacetic acid (5-HIAA) at Lab Tests online.

QIS document number: 21785

Last updated: 12 December 2020