The Urea Breath Test and H. Pylori

Medically Reviewed by Minesh Khatri, MD on May 28, 2023
Written by WebMD Editorial Contributors
2 min read

The urea breath test is used to detect Helicobacter pylori (H. pylori), a type of bacteria that may infect the stomach and is a main cause of ulcers in both the stomach and duodenum (the first part of the small intestine).

H. pylori produces an enzyme called urease, which breaks urea down into ammonia and carbon dioxide. During the test, a tablet containing urea is swallowed and the amount of exhaled carbon dioxide is measured. This indicates the presence of H. pylori in the stomach.

To prepare for the urea breath test, follow these guidelines:

  • Tell your doctor if you are pregnant, have a lung or heart condition or any other disease, or if you are allergic to any medications.
  • Do not take any antibiotics for at least 4 weeks before the test.
  • Do not take any proton pump inhibitors (Aciphex, Nexium, Prevacid, Prilosec, Protonix) or Pepto-Bismol​​​​​​​ for at least 2 weeks before the test.
  • Take only the medications approved by your doctor the day of the procedure. Take them only with a small sip of water if it is within four hours of the procedure. Do not discontinue any medication without first consulting with your primary or referring doctor.
  • Do not eat or drink anything (including water) for four hours before the procedure.

During the urea breath test:

  • A health care provider will explain the procedure, which lasts about 40 to 60 minutes, and answer any questions you may have.
  • Breath samples will be taken.

After the urea breath test:

  • Your breath samples are sent to a lab where they are tested.
  • You may resume your normal activities.
  • You may resume your normal diet, unless you are scheduled for other tests that require dietary restrictions.

Urea breath test results are usually available two days after the test is completed.