A urea breath test is one way doctors may test for Helicobacter pylori (H. pylori) infection. H. pylori is a type of bacterium that can cause digestive disorders.

This article will explain the test, who might need one, and how doctors carry it out. It will also look at the treatment options for H. pylori infection.

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The urea breath test (UBT) is a diagnostic tool. Doctors use it to see if a person has an H. pylori infection. They may recommend the test to detect the infection or check how well treatment is working.

The H. pylori bacterium converts urea, a naturally occurring compound, into carbon dioxide. Before the test, the person will take a tablet or liquid containing specially-labeled urea. The test then detects whether a person exhales carbon dioxide with the same label.

Other ways doctors may test for H. pylori include:

H. pylori is a bacterium that can cause an infection of the digestive system. More than 50% of the world’s population and around 30% of people in the United States have the bacterium in their gut.

H. pylori mainly lives in people. However, individuals can pass the infection on through contaminated food or water. While most people catch it from another household member, many have had it since childhood.

Many people with the infection never experience symptoms. For others, the bacteria can cause:

  • gastritis, or inflammation of the stomach lining
  • peptic ulcers, which are sores in the stomach, small intestine, or esophagus, the tube that connects the throat to the stomach
  • stomach cancer

Learn more about H. pylori here.

Doctors will usually recommend a UBT if someone has the following symptoms:

People already receiving H. pylori treatment may take a UBT to see if the infection is improving.

A UBT is suitable for adults and children, but children must be able to swallow the capsule whole and blow through a straw.

No studies have examined whether a UBT is safe for people who are pregnant or breastfeeding. Doctors will only recommend the test for these individuals if necessary.

During a UBT, the person will:

  1. exhale into a breath sample collection bag through a straw
  2. swallow a pill or liquid, without chewing, that contains the specially-labeled urea compounds
  3. exhale into another breath sample collection bag 10–15 minutes later

A laboratory will then compare the two samples. If the second sample contains more carbon dioxide than the first, the person may have an H. pylori infection.

Some people will need to stop taking certain medications 2 weeks to 1 month before having a UBT. Examples of these medications include:

People should speak with a doctor about which medications to stop taking and when.

Doctors will also usually recommend not eating for 6 hours before the test.

After the UBT, the person will be free to leave the healthcare clinic and resume their everyday activities.

A UBT does not affect a person’s ability to drive, and there is no recovery period.

If the UBT is negative, the person does not have an H. pylori infection. Doctors will use other tests to find the cause of the symptoms.

If the UBT is positive, the person may have an H. pylori infection. The doctor will usually perform a second test to be sure. This may be a blood test or a stool test.

Sometimes, the doctor may recommend an endoscopy. During this test, a healthcare professional inserts a long, thin, and flexible tube into the gut via the throat. The tube will have a light and a camera on the end, so the healthcare professional can inspect the person’s digestive system.

Doctors will recommend people with H. pylori infection take medication. This usually involves taking a PPI drug and the antibiotics amoxicillin and clarithromycin for 2 weeks.

Doctors will then check to see if the infection has gone, usually by carrying out another UBT. If it has not, the person will need to take more medication.

A person can talk with a doctor about using over-the-counter pain-relief medications if their infection is causing pain.

Learn about the best natural H. pylori treatments here.

H. pylori infection is treatable in most cases. However, it may take more than one course of medication.

The National Library of Medicine warns that H. pylori treatment can be complex. However, it is important that people take all medications as a doctor recommends, even if the symptoms improve. If the bacterium stays in the gut, it can cause peptic ulcers or stomach cancers.

Doctors usually recommend a UBT 4 weeks after the treatment ends to ensure the bacterium has gone.

A UBT is a test for H. pylori infection. Lots of people have this infection, but only some will have symptoms. The UBT is a noninvasive breath test that takes around 15 minutes.

If the person tests positive for H. pylori, doctors usually want to confirm the result with a blood or stool test.

Treatment involves taking antibiotics and PPIs. It can be complex, but it is usually successful. If the bacterium remains, it can lead to peptic ulcers and stomach cancer.