Test Details & Preparation

• Serotonin test is done to help diagnose a serotonin-secreting carcinoid tumour.


• Serotonin test is performed when you have symptoms suggestive of a carcinoid tumour such as flushing, diarrhoea, or wheezing.


• A blood sample drawn from a vein in your arm for a Serotonin test.


• No preparation is needed for a Serotonin test.


• A significantly increased level of serotonin in a person with carcinoid syndrome symptoms is suggestive but not diagnostic of a carcinoid tumour.


• Someone with symptoms may still have a carcinoid tumour even if the concentrations of serotonin and 5-HIAA are normal. The affected person may have a tumour that does not secrete serotonin or one that secretes it intermittently.


• A person with no symptoms and normal or low levels of serotonin and 5-HIAA is unlikely to have a serotonin-secreting carcinoid tumour.


• There are a variety of drugs that can affect the serotonin test, including morphine, monoamine oxidase (MAO) inhibitors such as reserpine, methyldopa, and lithium.