Hydrogen and Urea Breath Tests

Hydrogen Breath Test

A hydrogen breath test is used to detect lactose intolerance lactose intolerance (inability to digest lactose, the sugar found in milk), as well as fructose or sucrose intolerance. A hydrogen breath test can also detect bacterial overgrowth in the small intestine (a condition in which the normal flora of the intestine is altered; affects absorption of nutrients).

How to Prepare for a Hydrogen Breath Test

You should avoid eating slow-to-digest foods like beans, bran, or other high-fiber substances the day before testing. You will be asked to fast for 12 hours prior to the procedure, with only water to drink.

You should not smoke, sleep, or exercise vigorously for at least ½ hour before or at any time during testing.

Antibiotic use/therapy may interfere with test results. Please make sure the office staff is aware of any recent antibiotic use. Your doctor will let you know if or when you should adjust or stop any medications you take.

What to Expect

You will ingest a small amount of the test sugar, usually one of the following: milk, soda (not diet), sugar water, or lactulose (depending on which condition your physician suspects). You will then provide breath samples every 20 minutes over a 3-hour period to measure the amount of hydrogen exhaled in your breath.

Urea Breath Test

The urea breath test is a simple breath test that detects the presence of Helicobacter pylori, a bacteria found in the stomach. H. pylori has been found to cause peptic ulcers in some patients, while others show the presence of H. pylori with no symptoms at all.

How to Prepare for a Urea Breath Test

Do not eat or drink anything (including water) for 4 hours before the procedure. Your doctor will let you know if or when you should adjust or stop any medications you take.

What to Expect

The test takes approximately 30 minutes. After a baseline breath sample is obtained, you will drink 4 ounces of Pranactin®–Citric, a solution of urea and a non-radioactive carbon isotope. Another breath sample will be obtained 15 minutes later. Results are available in 2 to 3 days.

If H. pylori is present in the stomach, the urea is broken up and turned into carbon dioxide. The carbon dioxide is absorbed in the blood, travels to the lungs, and exhaled in the breath.