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5-HIAA

Urine_metabolic Unit: mg/24hr Urine test

Elevated in carcinoid syndrome

Also known as: 5-Hydroxyindoleacetic Acid

Reference Ranges

Clinical Reference 2.0 – 8.0 mg/24hr
Optimal Range 3.0 – 7.0 mg/24hr

Serotonin metabolite; avoid serotonin-rich foods before test

Related Conditions

Carcinoid Syndrome High

Food & Lifestyle Recommendations

🍎 Food Avoid serotonin-rich foods before testing (bananas, pineapple, walnuts, avocado) Diet affects 5-HIAA results

Evidence-Backed Supplements

When High

Questions to Ask Your Doctor

  • Does my elevated 5-HIAA suggest a carcinoid tumor, and what imaging should I have? Elevated 5-HIAA is the primary screening test for carcinoid syndrome; CT/MRI needed.

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