Slideshows Images Quizzes
font size

    Urea Breath Test (UBT)

    Medical Author:
    Medical Editor:

    What is the urea breath test?

    The urea breath test (UBT) is a test for diagnosing the presence of a bacterium, Helicobacter pylori (H. pylori) in the stomach. H. pylori causes inflammation, ulcers, and atrophy of the stomach. The test also may be used to demonstrate that H. pylori has been eliminated by treatment with antibiotics.

    What is the basis of this test?

    The urea breath test is based on the ability of H. pylori to break down urea, a chemical made up of nitrogen and carbon, into carbon dioxide which then is absorbed from the stomach and eliminated in the breath. (Urea normally is produced by the body from excess or "waste" nitrogen-containing chemicals and then eliminated in the urine.)

    How is this breath test done?

    For the test, patients swallow a capsule containing urea made from an isotope of carbon. (Isotopes of carbon occur in minuscule amounts in nature, and can be measured with special testing machines.) If H. pylori is present in the stomach, the urea is broken up and turned into carbon dioxide. The carbon dioxide is absorbed across the lining of the stomach and into the blood. It then travels in the blood to the lungs where it is excreted in the breath. Samples of exhaled breath are collected, and the isotopic carbon in the exhaled carbon dioxide is measured.

    How are the results of the urea breath test interpreted?

    If the isotope is detected in the breath, it means that H. pylori is present in the stomach. If the isotope is not found, H. pylori is not present. When the H. pylori is effectively treated (eradicated) by antibiotics, the test changes from positive (isotope present) to negative (isotope absent).

    Are there any risks or complications of the urea breath test?

    There are no risks or complications of the urea breath test. There is no need to stop any medications (including proton pump inhibitors) prior to performing the urea breath test.

    Medically reviewed by Joseph Palermo, D.O.; American Osteopathic Board Certified Internal Medicine


    Crowe, Sheila E., MD, FRCPC, FACP, FACG, AGAF. "Indications and diagnostic tests for Helicobacter pylori infection." Updated Mar. 12, 2015.

    Medically Reviewed by a Doctor on 9/9/2016


      GI Disorders

      Get the latest treatment options.

      Use Pill Finder Find it Now See Interactions

      Pill Identifier on RxList

      • quick, easy,
        pill identification

      Find a Local Pharmacy

      • including 24 hour, pharmacies

      Interaction Checker

      • Check potential drug interactions
      Search the Medical Dictionary for Health Definitions & Medical Abbreviations

      Health Solutions From Our Sponsors