What's this test for?

This test is ideal if you're experiencing flushing, chronic diarrhea, abdominal cramping, or wheezing that doesn't have a clear cause. These symptoms can sometimes be linked to carcinoid tumors, which release excess serotonin into the body. Measuring 5-HIAA in your urine over 24 hours helps show whether serotonin breakdown products are unusually high.

What happens after I get my results?

Your results will show up in your account with the normal range clearly explained next to your value. If your 5-HIAA level is elevated, next steps typically include avoiding certain foods and medications that can skew results and considering a repeat collection to confirm the finding, or seeking prompt medical care if you have severe symptoms like ongoing flushing and diarrhea. You can download a standard lab report from your account at any time, and if you retest in the future, the trends feature lets you compare results side by side.

What symptoms indicate I may need this test?

Common signs include recurring facial or upper body flushing, watery diarrhea, stomach cramps, and wheezing episodes that seem to come out of nowhere. Some people also notice a fast heartbeat or skin changes during these episodes. If these symptoms happen repeatedly and don't match a typical stomach bug or allergy, this test can help investigate serotonin-related causes.

How can I naturally support healthy serotonin balance?

Eating a balanced diet and avoiding large amounts of serotonin-rich foods like bananas, plantains, tomatoes, avocados, and walnuts in the days before testing can help keep results accurate. Regular exercise, good sleep, and stress management support overall hormone and nervous system balance. Limiting caffeine and alcohol can also help reduce digestive symptoms that mimic carcinoid-related issues.

When will I get my results?

Results are typically ready within about 7 days after the lab receives your 24-hour urine sample. You'll get a notification as soon as your results are posted to your account. The report will include your value alongside the reference range so you can see exactly where you stand.

Who should consider this test?

This test is a good option for people with unexplained, repeated flushing episodes, chronic watery diarrhea, or wheezing that hasn't been explained by other causes. It's also useful if you have a family history of carcinoid tumors or related conditions. Anyone whose symptoms come and go in a pattern that doesn't fit common digestive or allergy issues may benefit from this screening.

What is 5-HIAA and why does it matter?

5-HIAA (5-Hydroxyindoleacetic Acid) is a byproduct your body makes when it breaks down serotonin, a chemical involved in mood, digestion, and blood vessel function. Measuring it in urine over a full day gives a picture of how much serotonin your body has produced and processed. Unusually high levels can point to carcinoid tumors, which are rare but treatable when caught early.

What does a high 5-HIAA result mean?

A high result, especially above 10 mg per 24 hours, can suggest carcinoid syndrome, a condition where certain tumors release excess serotonin. Smaller elevations can also happen with conditions like nontropical sprue or after taking certain medications. If your result is high, it's worth reviewing what medications and foods you had before the test, since many common drugs and foods can cause false elevations.

What causes a false or misleading 5-HIAA result?

Many everyday medications can raise or lower your 5-HIAA reading, including acetaminophen, certain blood pressure medications, antidepressants, decongestants, and even aspirin. Eating foods high in serotonin, like bananas, tomatoes, and nuts, in the day or two before your collection can also push results higher than your true baseline. If you suspect interference, retesting after avoiding these foods and medications, when safe to do so, can help confirm your actual level.

How often should I retest?

If your first result is elevated, a repeat 24-hour collection after avoiding interfering foods and medications is usually the next step to confirm the finding. If your results are normal but symptoms continue, retesting periodically or exploring other causes may be helpful. Tracking results over time in your account can help you and anyone reviewing your history spot patterns.

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.

5-HIAA Urine Test - Carcinoid Syndrome 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]

5-HIAA 24-Hour Urine Test for Carcinoid Symptoms

5-Hydroxyindoleacetic Acid (5-HIAA), 24-Hour Urine without Creatinine

Prescription & fees included

Easy to understand results

Fast & convenient

Prescription & fees included

Easy to understand results

Fast & convenient

What's this test for?

What happens after I get my results?

What symptoms indicate I may need this test?

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

Find a lab near you

5-HIAA 24-Hour Urine Test for Carcinoid Symptoms

Prescription & fees included

Easy to understand results

Fast & convenient

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