It may be difficult for doctors to recognize your symptoms as carcinoid syndrome because it is a rare condition. Fortunately, there are tests that can help diagnose carcinoid syndrome. Your doctor may choose one of the following methods.
If you have carcinoid syndrome, you might have high levels of 5-HIAA. 5-HIAA shows up in your system after your body processes serotonin. Your doctor can diagnose you using a 5-HIAA urine test or a plasma test. You can continue to monitor your 5-HIAA levels by getting them tested every few months.
Serotonin levels can also be measured directly in the blood with a blood test. High levels of serotonin may indicate carcinoid syndrome.
A neuroendocrine tumor or carcinoid tumors are rare and sometimes difficult to diagnose. Here are a few tests commonly used to help diagnose a neuroendocrine tumor.