H. pylori Breath Test
A plain-language guide to the urea breath test for H. pylori: what it measures, how to prepare, what your results mean, and what it costs.
At a Glance
What is the H. pylori breath test?
The simple breathing test that finds stomach bacteria
The H. pylori breath test, also called the urea breath test, checks whether the H. pylori bacteria are living in your stomach right now. You swallow a small drink or capsule, then blow into a bag or tube after about 15 to 30 minutes. If the bacteria are present, the lab detects a marker in your breath, and you get results in a few days.
H. pylori, short for Helicobacter pylori, is a common bacterium that lives in the lining of your stomach. It can cause irritation, ulcers, and over many years it raises the risk of stomach cancer. Many people carry it for years with no symptoms at all. The breath test is one way doctors find out if it is in your stomach today.
The full name is the urea breath test. Here is the simple idea behind it. H. pylori makes an enzyme called urease that breaks down a substance called urea. In the test, you swallow a drink or capsule that contains urea tagged with a harmless, traceable form of carbon. If the bacteria are in your stomach, they break the urea apart and release that carbon as carbon dioxide. You breathe it out, and the lab measures it.
There are two main versions. The carbon-13 version uses a non-radioactive marker and is safe for children and pregnant patients. The carbon-14 version uses a tiny amount of radioactive marker. Both work well, and your clinic will tell you which one they use.
On this page
- What is the H. pylori breath test?
- Why would a doctor order this test?
- How do you prepare for the test?
- How is the test done, step by step?
- What do your results mean?
- How accurate is it, and can it be wrong?
- Is the breath test safe?
- What does it cost and where can you get it?
- Top Gastroenterologists for this
- Frequently asked questions
Why would a doctor order this test?
The symptoms and situations that point to H. pylori
Doctors usually order an H. pylori breath test when your symptoms or history suggest the bacteria could be behind your stomach trouble. You do not need this test for everyday heartburn after a big meal. It is for symptoms that stick around or point to an ulcer.
Common reasons your provider may order it:
- Ongoing stomach pain or a burning feeling in the upper belly, especially between meals or at night
- A diagnosed stomach or duodenal ulcer, since H. pylori causes most of them
- Long-lasting bloating, nausea, or feeling full fast that has not improved
- A family history of stomach cancer, which raises your own risk if you carry the bacteria
- Before starting long-term pain relievers like daily aspirin or NSAIDs, which can combine with H. pylori to cause bleeding ulcers
If you have alarm signs such as vomiting blood, black stools, trouble swallowing, or unexplained weight loss, your doctor may skip straight to an endoscopy instead. That lets them look directly at the stomach and take tissue samples. The breath test is for finding the bacteria, not for examining the stomach wall.
How do you prepare for the test?
The medication pause and fasting rules that protect your result
Good preparation is the most important part of this test. The wrong medication or a recent meal can hide the bacteria and give you a false all-clear. Follow your clinic's instructions closely, and ask questions if anything is unclear.
Stop acid-reducing medicine. Proton pump inhibitors such as omeprazole, esomeprazole, lansoprazole, and pantoprazole suppress the bacteria and can mask an infection. Most clinics ask you to stop these for two weeks before the test. Do not stop any prescription medicine without checking with your provider first.
Pause antibiotics and bismuth. Any antibiotic in the last four weeks can suppress H. pylori and cause a false negative. Bismuth products like Pepto-Bismol do the same. Tell your doctor every medicine and supplement you take, including over-the-counter ones.
Fast before you arrive. You will usually be asked not to eat or drink anything, including water, for at least one hour before the test. Many clinics ask for a longer fast of six hours or overnight. Confirm the exact window with your clinic.
- H2 blockers like famotidine may need to stop a few days ahead; ask your clinic
- Antacids like Tums are often allowed up to the day before, but confirm
- Do not smoke on the morning of the test, since it can affect breath samples
If you cannot safely stop your acid medicine, tell your doctor. They may choose a different test or adjust the timing so your result still means something.
How is the test done, step by step?
What happens from check-in to your last breath sample
The H. pylori breath test is quick, painless, and done while you sit in a chair. There are no needles and no scope. Here is what usually happens from start to finish.
Step 1: Baseline breath. A technician asks you to breathe out through a straw into a collection bag or sealed tube. This first sample captures your normal breath before you swallow anything. It gives the lab something to compare against.
Step 2: The urea drink or capsule. You swallow the test substance. It may be a small glass of a citrus-flavored liquid or a pill, depending on the clinic. It is tasteless or mildly sour and does not make you feel sick.
Step 3: The wait. You sit quietly for about 15 to 30 minutes. This gives any bacteria time to break down the urea and release the carbon marker into your breath. You may be asked not to talk much, eat, drink, or smoke during this window.
Step 4: The final breath sample. You breathe out into a second bag or tube. The technician seals it and sends both samples to the lab, which measures how much of the tagged carbon dioxide is in your breath.
The whole visit takes 15 to 40 minutes. You can drive yourself home and go back to your normal day right away, including eating and restarting any medicines your doctor told you to pause. The samples are then analyzed, and results usually reach your doctor within one to three days.
What do your results mean?
Positive, negative, and what each one tells your doctor
Breath test results are reported as positive or negative, and they are straightforward to read.
A positive result means H. pylori is active in your stomach. The bacteria broke down the urea and released the carbon marker that the lab detected. If this is your first test, your doctor will likely recommend treatment, usually a combination of two antibiotics plus an acid-reducing medicine taken for 10 to 14 days. Treating the infection helps ulcers heal and lowers your long-term risk of stomach cancer.
A negative result means the test found no sign of active infection. If your symptoms continue, your doctor may look for other causes such as acid reflux, gallbladder problems, or a different stomach condition. They may also double-check that nothing masked the test, since a recent antibiotic or acid reducer can produce a false negative.
Unlike a blood test, the breath test reflects what is happening in your stomach now. That is why it is trusted both to diagnose an infection and to prove it is gone.
How accurate is it, and can it be wrong?
False positives, false negatives, and what throws the test off
The urea breath test is one of the most accurate non-invasive ways to find H. pylori. When the prep rules are followed, it is correct roughly 95% of the time for both finding and ruling out an active infection. Still, no test is perfect, and a handful of things can throw off the result.
What causes a false negative (the test says you are clear when you are not):
- Taking a proton pump inhibitor within two weeks of the test
- Taking antibiotics or bismuth within four weeks
- Recent stomach bleeding, which can temporarily suppress the bacteria
What causes a false positive (the test says you have it when you do not):
- Other urease-producing bacteria in the mouth or stomach, which is uncommon
- A burp or reflux that brings up the test substance too early
The biggest avoidable problem is medication. This is why your clinic is strict about stopping acid reducers and antibiotics. If you could not stop them, tell your doctor so your result is read with that in mind.
Is the breath test safe?
Side effects, who should be careful, and the home-test warning
The H. pylori breath test is very safe for nearly everyone. There are no needles, no sedation, and no recovery time. The test substance is harmless to swallow, and side effects are rare and mild. Some people notice a slightly sour taste or a little fullness from the drink, and that passes quickly.
The carbon-14 version uses a tiny amount of a radioactive marker. The dose is extremely small, far less than a typical X-ray. Even so, this version is usually avoided in young children and in people who are pregnant or breastfeeding. For those groups, the carbon-13 version is used instead because it has no radiation at all. Tell your clinic if you are or could be pregnant.
Do not rely on home or self-ordered tests to skip your doctor. Some at-home kits test blood or stool for H. pylori, but they cannot tell you whether you need an endoscopy, and they do not catch the medication mistakes that cause false results. The bigger issue is that treating H. pylori requires prescription antibiotics chosen for your situation. Buying antibiotics on your own, or guessing at a dose, can fail to clear the infection and push the bacteria toward antibiotic resistance.
See a doctor promptly if you have black or bloody stools, are vomiting blood, cannot swallow, or are losing weight without trying. Those symptoms call for an in-person exam and likely an endoscopy. A breath test alone is not enough.
What does it cost and where can you get it?
Cash prices, insurance, and Medicare coverage
The H. pylori breath test is affordable compared with most stomach tests, and it is widely covered when your doctor orders it for symptoms. Prices vary by where you go, whether you use insurance, and whether the sample is processed at a hospital or an outside lab.
If cost is a worry, ask your clinic about self-pay lab pricing, which is sometimes lower than your insurance copay. Community health centers and federally qualified health centers offer sliding-scale fees based on income. This test can catch a bacterium linked to ulcers and stomach cancer. It is rarely worth skipping, and there is almost always a low-cost path to getting it done.
With more than 21,000 gastroenterologists in our directory, you can find a specialist near you who orders and interprets this test, then guides treatment if your result comes back positive.
| Situation | Typical cost |
|---|---|
| Self-pay / cash price | $60 to $200 |
| With insurance (copay or coinsurance) | $0 to $100 |
| Hospital outpatient lab | $150 to $300 |
| Medicare (when ordered for symptoms) | Covered, small or no coinsurance |
Ranges are typical US 2026 estimates and vary by region and lab. The marker drink and the lab analysis may be billed separately. Always confirm the full price with your clinic and check whether the test is in network before your visit.
Top 6 Gastroenterologists Who Provide H. pylori Breath Test
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Frequently Asked Questions
How long does the H. pylori breath test take?
The visit usually takes 15 to 40 minutes. Most of that is the wait after you swallow the urea drink, which is about 15 to 30 minutes. The breathing samples themselves take only a minute or two each.
Do I have to fast before the test?
Yes. You should not eat or drink for at least one hour before the test, and many clinics ask for a longer fast of six hours or overnight. Fasting keeps food from interfering with the breath samples. Confirm the exact window with your clinic.
Which medicines do I need to stop before the test?
Stop proton pump inhibitors like omeprazole for two weeks, and avoid antibiotics and bismuth products like Pepto-Bismol for four weeks. These can hide the bacteria and cause a false negative. Never stop a prescription medicine without asking your doctor first.
Is the breath test better than a blood test for H. pylori?
For most situations, yes. The breath test shows an active infection happening now, while a blood test can stay positive long after the bacteria are gone. The breath test is also the standard way to confirm that treatment cleared the infection.
Is the test safe during pregnancy?
The carbon-13 version has no radiation and is considered safe in pregnancy and for young children. The carbon-14 version uses a tiny amount of radioactive marker and is usually avoided during pregnancy and breastfeeding. Tell your clinic if you are or could be pregnant so they use the right version.
When will I get my results?
Most labs return results to your doctor within one to three days. Your provider will then explain whether the result was positive or negative and what the next step is, including treatment if H. pylori was found.
What happens if the test is positive?
A positive result means H. pylori is active in your stomach. Your doctor will usually prescribe a 10 to 14 day course of two antibiotics plus an acid reducer. About four weeks after you finish, a repeat breath test confirms the bacteria are gone.
Can I do an H. pylori test at home instead?
Some at-home kits test blood or stool, but they cannot catch the medication mistakes that cause false results, and they do not replace a doctor's judgment about whether you need an endoscopy. Treatment requires prescription antibiotics, so it is best to test and treat with a doctor's guidance.
Medical disclaimer: This content is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you have a medical emergency, call 911. Our editorial standards