5-Hydroxyindoleacetic Acid (5-HIAA), 24 Hours Urine

This test measures the levels of 5-Hydroxyindoleacetic Acid (5-HIAA) in your urine over 24 hours.

• To detect and monitor carcinoid tumours of the mid-gut
• To evaluate the effectiveness of treatment for carcinoid tumours
• To diagnose and monitor other conditions that affect serotonin levels
• To assess the risk of developing carcinoid syndrome

Your doctor might recommend this test if you have

• A previous diagnosis of carcinoid tumours
• A family history or genetic risk factors for carcinoid tumours
• Symptoms suggestive of other serotonin-related conditions such as depression, anxiety, and sleep disorders

An abnormal result (high levels of 5-HIAA) in a 24-hour urine test suggests the presence of carcinoid tumors, particularly in the midgut (small intestine, appendix, pancreas)

It may aslo suggest of other conditions that affect serotonin levels.

Here’s what you should expect during this test:

•    You will be given a special container to collect all your urine over 24 hours.

•    The sample should be kept refrigerated until it is brought to the laboratory for testing.

To prepare for this test, remember the following points:

• Consult your healthcare provider for specific directions before the test.
• Do not consume bananas, pineapple, chocolates, coffee, ice cream, high diet in cereals and vanilla, potatoes and B complex vitamin 48 hours before collection. 

You might be asked to provide a CT scan, ultrasound report, and medication history to help your doctor interpret the test results.

Other tests that may be ordered alongside 5-HIAA test include

• Chromogranin A Testing: This blood test measures the chromogranin A hormone and is used to help diagnose and monitor carcinoid tumours.
• Gastrin Testing: This blood test measures the hormone gastrin and helps diagnose gastrinomas – tumours that produce excess amounts of gastrin. 
• CT Scan or MRI: Imaging tests like CT scans or MRI may be used to locate and identify tumours in different parts of the body.

• 24-hour urine 5-hydroxyindoleacetic acid test
• 24-hour urine 5-HIAA test

Cancer of the mid-gut or mid-gut carcinoid develops in the digestive tract, usually growing slowly in the small intestine, appendix, or colon. The tumors can be non-cancerous or cancerous and may produce too many hormones, such as 5-HIAA in your blood.