The hydrogen breath test is a test that uses the measurement of hydrogen in the breath to diagnose several conditions that cause gastrointestinal symptoms.

How is hydrogen breath testing performed?

Prior to hydrogen breath testing, the patient fasts for at least 12 hours. At the start of the test, the patient blows into and fills a balloon with a breath of air. The concentration of hydrogen is measured in a sample of breath removed from the balloon. The patient then ingests a small amount of the test sugar (lactose, sucrose, sorbitol, fructose, lactulose, etc. depending on the purpose of the test).

Additional samples of breath are collected and analyzed for hydrogen every 15 minutes for three and up to five hours.