1. Why do I have to collect my urine for 24 hours?
The concentration of 5-HIAA in the urine varies throughout the day. By collecting all urine for 24 hours, the amount of 5-HIAA in the urine can be averaged over the entire day and increases of 5-HIAA will be detected more easily than in a single random urine sample.
Yes, the other major metabolite is 5-hydroxytryptphol (5-HTOL). This substance is not routinely tested for but may sometimes be performed and the result included in a ratio with the 5-HIAA test to evaluate ethyl alcohol ingestion. An increased ratio of 5-HTOL to 5-HIAA can be indicative of alcohol consumption in both living people and post-mortem.
3. Will my results be accurate if I must continue to take my medication?
If the drug is one that can increase or decrease the amount of serotonin and 5-HIAA, then your results may be affected. However, it is up to your healthcare provider and you to decide whether or not your medication can be safely stopped prior to and during the test collection. If your drugs must be taken, then your health practitioner will interpret the test results with this in mind.
4. Are some people at a higher risk for developing a carcinoid tumor?
Anyone at any age can develop a carcinoid tumor but, according to the American Cancer Society, the average age at diagnosis is usually in the early 60s. People with a family history of multiple endocrine neoplasia (MEN1), a genetic condition that increases a person's risk of developing tumors in the endocrine system glands, may be at higher risk for developing a carcinoid tumor.
This article was last reviewed on May 28, 2014. | This article was last modified on May 28, 2014.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
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