Please read the information and follow the instruction given carefully as failure to do so may result in an inaccurate result and the need to repeat the test.
What is a 24-hour urine collection?
A 24-hour urine collection is a complete collection of all the urine produced in one 24-hour period. This involves collecting all the urine in a specially provided container, which may contain a preservative.
Preservatives are used for some tests to ensure that the substance being tested does not de-grade before it can be measured.
Why is a 24-hour urine collection needed?
Urine contains many waste products and chemicals produced by the body. In some situations, measurement of a particular chemical can help in identification or monitoring of a disease.
For some tests a random urine sample is adequate, but in others a 24-hour collection is necessary as it is important to find out how much of the substance is produced in a day.
What do we look for?
The first step with all 24-hour urine samples is to measure the volume of urine that has been provided. This is an important piece of information, as it is needed to calculate the total daily output of the substance under investigation.
The sample is then tested in the laboratory and the results are calculated.
What is a 24-hour urine collection for 5-hydroxyindoleacetic acid (5-HIAA)?
Patients may have a substance called 5-hydroxytryptamine in excess amounts in their body due to a rare type of growth somewhere in the body which is called a carcinoid. This can result in the symptoms of diarrhoea or facial flushing.
5-hydroxytryptamine is broken down to 5-HIAA and this is detected in the urine.
Measurement of urine 5-HIAA is therefore useful in determining the diagnosis and whether treatment is required for the underlying condition.
You may have been asked to make urine collections on more than one day because patients often have intermittently raised 5- HIAA levels.
Is there anything I should avoid before 24 hr urine collection for 5HIAA?
Some foods contain a substance related to 5HIAA which can be excreted in the urine and may affect the test results. These foods should be avoided in the 3 days prior and during the 24 hour collection:
- Avocados, bananas, aubergine (eggplant), kiwi fruit, pineapple, plums, walnuts, tomatoes, and certain health food supplements containing 5 Hydroxytryptophan
- Pineapple juice, alcoholic beverages
Please avoid taking paracetamol if possible and write down any medications that you are taking on the request form, especially if they are for high blood pressure or depression.
What you need to do to prepare for this test?
You will be given a special container in which to collect the urine. It may contain a preservative or acid (for example in an investigation of 5-HIAA) and this must be left in the container and not thrown away.
The label will tell you if a preservative is in the container and care should be taken not to spill or touch any as it could burn the skin.
Any spillage must be mopped up with plenty of water and if contact occurs rinse the skin with copious amounts of water and inform your doctor.
You may find it is useful to collect the urine in a smaller container and straight away, carefully pour it into the large container you have been provided with.
When to collect the sample
Choose a convenient time to start the urine collection such as when you rise in the morning e.g. 8:00am. The end of the collection will be 24 hours later.
Then proceed as follows:
Day 1 8:00am
Empty the bladder completely and discard the urine. For the rest of the day collect all urine passed into the container.
Day 2 8:00am
Empty the bladder completely and add this urine to the container. Add no more urine. This completes the collection.
Make sure that during and after the collection (until it is delivered to the hospital) the urine container is kept in a cool place. If any urine is accidentally discarded during the collection, stop the test, and tell the laboratory what has happened. You will be given another container to start again.
After the sample has been collected
Carefully label the container with the following:
• Name (forename and surname)
• Date of birth
• Date and time of collection (start and finish time)
• The ward or clinic you are attending (e.g. the Outpatients department - OPD)
Unfortunately, any sample received unlabelled cannot be accepted for analysis.
What to do with the collected sample
Deliver the container and the request form if you were given one, as soon as possible after completion.
Salford patients should deliver to:
Salford Royal Pathology Specimen Reception, Turnberg Buiiding, Level 2, Stott Lane, Salford, M6 8HD
Oldham patients should deliver to:
Royal Oldham Pathology Specimen Reception, Pathology Building, Rochdale Road, Oldham, OL1 2JH
Fairfield patients should deliver to:
Fairfield General Pathology, Broad Oak Suite, Rochdale Road, Bury, BL9 7TD
Laboratory opening hours are 8 am - 8pm Monday to Sunday.
If you have been instructed to take the container to a ward or clinic, then take the container and request form there.
What are the limitations of this Investigation?
The accuracy of the results depends on the quality of your sample, so it is very important that you follow the instructions on collection and delivery of the sample exactly.
Are there any alternatives to this Investigation?
There are no alternatives to this test that will give as much information.
What happens to your results?
The results of the analysis will be sent to your doctor, who will explain to you what they mean and what, if any, treatment you may need. Laboratory staff are not permitted to give you results or discuss the meaning of the results with you.
If you require further information about this test, please contact:
Salford Royal Clinical Biochemistry Department, Stott Lane, Salford, M6 8HD
Tel: 0161 206 0844 or email:joanna.borzomato@nca.nhs.uk
Royal Oldham Clinical Biochemistry Department, Pathology Building, Rochdale Road, Oldham, OL1 2JH
Tel: 0161 656 1515 or email jonathan.scargill@nca.nhs.uk
Date of Review: October 2023
Date of Next Review: October 2025
Ref No: PI_P_1641 (NCA)