5 HIAA
Private 5-HIAA urine test in London for £219.99, measuring one serotonin metabolite marker with results in around 1 week.
Turnaround time
1 week
Biomarkers count
1
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Overview of the 5-HIAA Blood Test
The 5 HIAA test is a specialist urine investigation that measures 5-Hydroxyindoleacetic Acid, commonly abbreviated to 5-HIAA.
5-HIAA is the principal breakdown product of serotonin, a chemical messenger produced predominantly within the gastrointestinal tract and also within the nervous system.
After serotonin has been used by the body, it is metabolised mainly in the liver and converted into 5-HIAA, which is then excreted in urine.
The test contains 1 biomarker: 5 HIAA. It is most commonly used when investigating or monitoring serotonin-secreting neuroendocrine tumours, historically referred to as carcinoid tumours.
A 24-hour urine collection provides a more representative assessment because serotonin production and 5-HIAA excretion can fluctuate throughout the day.
An elevated 5-HIAA result does not independently diagnose a neuroendocrine tumour. Diet, medicines, supplements and incomplete urine collection can influence the measurement, while some neuroendocrine tumours do not produce significant amounts of serotonin.
The result should therefore be interpreted alongside symptoms, preparation, other biochemical markers, imaging and the wider clinical picture.
What Does the 5-HIAA Check?
This test measures 1 biomarker.
5 HIAA
Measures urinary 5-Hydroxyindoleacetic Acid, the principal metabolite produced when serotonin is broken down. Increased levels may occur with serotonin-secreting neuroendocrine tumours, although the result should be interpreted alongside symptoms, dietary preparation, medication, imaging and other clinical investigations.
Who May Benefit From the 5-HIAA blood Test ?
This test may be suitable for people in whom excessive serotonin production or a serotonin-secreting neuroendocrine tumour is being investigated or monitored.
Recurrent unexplained flushing - Episodes of facial or upper-body flushing can occur with carcinoid syndrome, although many more common conditions can produce similar symptoms.
Persistent unexplained diarrhoea - Chronic watery diarrhoea may occasionally occur with serotonin-secreting neuroendocrine tumours.
Flushing together with diarrhoea or wheezing - A combination of characteristic symptoms may prompt specialist investigation of serotonin production.
Possible neuroendocrine tumour - 5-HIAA may form part of a wider diagnostic assessment alongside imaging and other biochemical markers.
Previously abnormal serotonin-related result - Repeat testing may help determine whether an earlier abnormality persists.
Known serotonin-secreting neuroendocrine tumour - Serial measurements may be used by specialists to monitor biochemical activity over time.
Monitoring response to treatment - Changes in 5-HIAA may provide useful information in people with a confirmed serotonin-producing tumour.
Specialist-requested neuroendocrine testing - The test can be arranged privately where an endocrinologist, gastroenterologist, oncologist or GP has specifically requested 5-HIAA measurement.
How to Prepare
Do not change prescribed medication or deliberately alter your diet beyond the specific laboratory preparation instructions simply to influence the result.
Correct dietary preparation and complete 24-hour collection are particularly important because both can materially affect urinary 5-HIAA measurement.
Symptoms and Reasons to Consider the 5-HIAA Blood Test
You may wish to consider the 5 HIAA test when symptoms or previous investigations raise concern about excessive serotonin production or a serotonin-secreting neuroendocrine tumour.
Episodes of unexplained flushing - Sudden warmth or redness affecting the face, neck or upper chest can occur with carcinoid syndrome.
Persistent or recurrent diarrhoea - Frequent watery bowel movements without an established explanation may warrant further investigation.
Unexplained wheezing - Serotonin and other substances released by neuroendocrine tumours can occasionally contribute to bronchospasm.
Episodes of a rapid heartbeat - Palpitations or tachycardia can accompany flushing episodes in some people.
Recurring abdominal discomfort - Gastrointestinal neuroendocrine tumours can occasionally be associated with abdominal symptoms, although these are highly non-specific.
Previously diagnosed neuroendocrine tumour - 5-HIAA may be monitored where a tumour is known to produce serotonin.
Abnormal previous neuroendocrine investigations - A specialist may request 5-HIAA alongside imaging or other biochemical investigations.
Unexplained combination of flushing and diarrhoea - These symptoms occurring together may be more clinically relevant than either symptom in isolation.
These symptoms have many possible causes, and most people experiencing flushing, diarrhoea, wheezing or abdominal discomfort will not have a neuroendocrine tumour.
5-HIAA is an important specialist marker, but neither an elevated nor normal result should be interpreted as a diagnosis by itself.
Severe persistent diarrhoea, significant dehydration, severe abdominal pain, breathing difficulty, collapse or rapidly worsening symptoms require appropriate medical assessment rather than waiting for routine private test results.
How to Book Your 5-HIAA in London
Booking your 5 HIAA test with London Blood Tests is simple, although the correct 24-hour urine collection equipment and preparation instructions are required before testing begins.
Choose the 5 HIAA
Select the 5 HIAA test online and review the included serotonin metabolite biomarker and preparation requirements.
Select your sample collection option
Arrange the appropriate 24-hour urine collection kit and laboratory-approved container required for the test.
Attend your appointment
Where kit collection or an appointment is required, attend the arranged location to receive the correct container and collection instructions.
Laboratory analysis
Once the 24-hour urine collection is complete, your specimen is returned to the laboratory where 5-HIAA is measured using specialist biochemical analysis.
Receive your results securely
Your results are sent securely by email, ready to review yourself or discuss with a GP, endocrinologist, gastroenterologist, oncologist or other suitably qualified healthcare professional.
When Will I Receive My Results?
The expected turnaround time for the 5 HIAA test is approximately 1 week after your completed urine collection arrives at the laboratory.
Results are sent securely by email once specialist laboratory analysis and authorisation are complete. Turnaround therefore begins when the laboratory receives the completed specimen rather than when you begin the 24-hour collection.
Specialist biochemical testing may occasionally require repeat analysis, confirmation or additional laboratory review, which can extend the expected turnaround.
Understanding Your Results
Your 5 HIAA result shows the amount of 5-Hydroxyindoleacetic Acid measured in your urine according to the laboratory reference interval and analytical method used.
An increased result can indicate increased serotonin production. In someone with symptoms compatible with carcinoid syndrome, a significantly elevated result may provide supporting evidence for further investigation of a serotonin-secreting neuroendocrine tumour.
However, an elevated 5-HIAA result does not independently establish a cancer diagnosis.
Certain foods, supplements and medicines can increase urinary 5-HIAA and produce a misleading result. Correct preparation is therefore particularly important.
A normal result does not completely exclude a neuroendocrine tumour. Some neuroendocrine tumours do not secrete serotonin, while others may produce it intermittently.
Incomplete urine collection can also produce an inaccurately low measurement.
For people with an established serotonin-secreting neuroendocrine tumour, trends in repeated 5-HIAA measurements may provide more useful information than a single result.
Results should therefore be interpreted alongside symptoms, diet, medicines, collection completeness, kidney function, imaging and other neuroendocrine investigations.
Why Book With London Blood Tests?
Private 5-HIAA testing in London - Access specialist urinary 5-HIAA testing through London Blood Tests.
Targeted serotonin metabolite measurement - Measure 5-HIAA without having to book a broad general health profile.
Relevant to neuroendocrine tumour investigation - 5-HIAA can provide supporting biochemical information when a serotonin-secreting neuroendocrine tumour is clinically suspected.
Useful for carcinoid syndrome assessment - Testing may be relevant where flushing, diarrhoea and other characteristic symptoms occur together.
Suitable for monitoring known serotonin-secreting tumours - Serial testing may provide useful biochemical information during specialist follow-up.
Specialist 24-hour urine analysis - Your specimen is processed using dedicated biochemical laboratory methods.
Clear collection instructions - Appropriate dietary preparation and 24-hour collection guidance are provided for accurate testing.
Secure results by email - Receive your authorised laboratory result securely once analysis is complete.
Clear pricing before booking - The 5 HIAA test is priced at £219.99, with any applicable collection or kit charges shown separately.
Private 5-HIAA Blood Test in London
London Blood Tests provides the 5 HIAA test in London for people requiring specialist investigation or monitoring of serotonin metabolism.
The test costs £219.99 and measures one biomarker: 5 HIAA. This is the principal breakdown product of serotonin and is most commonly assessed using a 24-hour urine collection.
Collection kits can be arranged with the appropriate instructions, providing access for people looking for a private 5-HIAA test in London or specialist neuroendocrine testing.
A 5-HIAA result should not be interpreted independently. An endocrinologist, gastroenterologist, oncologist or other specialist may recommend additional biochemical investigations and imaging depending on symptoms and the wider clinical picture.