What's this test for?

This test is ideal if you're experiencing unexplained flushing, diarrhea, wheezing, or rapid heartbeat that your doctor suspects may be related to carcinoid tumors. Carcinoid tumors are slow-growing tumors that produce excess serotonin, and this test measures the breakdown product of serotonin in your urine over a 24-hour period. It helps doctors confirm or rule out the presence of these tumors and monitor treatment if you've already been diagnosed.

What happens after I get my results?

You'll receive doctor notes in simple language explaining what your 5-HIAA levels mean and whether they suggest excess serotonin production. These notes include guidance on next steps, such as whether you need imaging studies, further testing, or a specialist consultation with an oncologist or endocrinologist. Along with your standard lab report, you can track your levels over time using our trends feature, which is especially helpful if you're monitoring treatment effectiveness or watching for tumor recurrence.

What's included in this test?

This test measures 5-Hydroxyindoleacetic Acid (5-HIAA), which is the main breakdown product of serotonin in your body, and creatinine to ensure accurate collection. This test measures 5-HIAA, which is the main breakdown product of serotonin in your body. It also includes a creatinine measurement to ensure the urine collection was complete and accurate. Together, these measurements help identify whether your body is producing excessive amounts of serotonin, which can indicate the presence of carcinoid tumors or other neuroendocrine conditions.

How should I prepare for this test?

You'll need to collect all urine over a 24-hour period in a special container. Before and during the collection, avoid certain foods and medications that can affect results, including bananas, avocados, pineapple, walnuts, kiwi, plums, tomatoes, and eggplant for 48-72 hours before testing. Also avoid caffeine, alcohol, tobacco, and medications like acetaminophen if possible. Your healthcare provider will give you specific instructions and the collection container.

When will I get my results?

Results from this 24-hour urine test are typically available within 3-5 business days after the lab receives your sample. You'll receive an email notification when your results are ready to view in your secure online account. Because this is a specialized test for tumor detection, your doctor may want to review the results with you directly to discuss next steps.

Who should consider getting this test?

This test is recommended for people experiencing symptoms like facial flushing, chronic diarrhea, wheezing, or heart palpitations that suggest carcinoid syndrome. It's also used for monitoring people who have been diagnosed with carcinoid tumors or other neuroendocrine tumors to track disease progression or treatment response. Your doctor may order this test if imaging studies or other blood tests suggest a possible tumor.

What symptoms indicate I may need this test?

Common symptoms that warrant this test include episodes of facial flushing or redness, persistent watery diarrhea, wheezing or asthma-like breathing problems, and rapid heartbeat. You might also experience abdominal pain, unexplained weight loss, or low blood pressure. These symptoms occur when carcinoid tumors release excessive serotonin and other substances into your bloodstream.

What is 5-HIAA and why does it matter?

5-HIAA is the waste product your body creates when it breaks down serotonin, a chemical messenger in your body. Normal levels of serotonin help regulate mood, digestion, and other functions, but certain tumors called carcinoid tumors can produce excessive amounts. By measuring 5-HIAA in your urine, doctors can detect whether your body is producing too much serotonin, which is a key indicator of these tumors.

What does high 5-HIAA mean?

Elevated 5-HIAA levels typically indicate your body is producing excess serotonin, which most commonly occurs with carcinoid tumors. High levels can also occasionally result from certain foods if dietary restrictions weren't followed before testing, or rarely from other conditions like medullary thyroid cancer or small cell lung cancer. Your doctor will interpret your results in the context of your symptoms and may order additional imaging or tests to locate any tumors.

How often should I retest 5-HIAA levels?

If you've been diagnosed with a carcinoid tumor, your doctor will typically monitor your 5-HIAA levels every 3-6 months to track disease activity and treatment response. If you've had surgery to remove a tumor, regular testing helps detect any recurrence early. For initial screening with normal results, retesting is usually only needed if new symptoms develop or your doctor has ongoing concerns.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

Carcinoid Tumor Test - 5-HIAA Urine Screening

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

[email protected]

Urine Test for Flushing, Diarrhea, and Tumor Screening

5-Hydroxyindoleacetic Acid (5-HIAA), 24-Hour Urine, with Creatinine

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

What's this test for?

How should I prepare for this test?

What's included in this test?

Here’s why 1,000,000+ customers chose us for affordable hassle-free private blood testing.

Urine Test for Flushing, Diarrhea, and Tumor Screening

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

1,000,000+ blood tests later, here's what our customers say