A breath test is a type of test performed on air generated from the act of exhalation.^[1]

Types include:

• Breathalyzer – by far the most common usage of this term relates to the legal breath test to determine if a person is driving under the influence of alcohol.
• Hydrogen breath test – it is becoming more and more common for people to undertake a medical test for clinical diagnosis of dietary disabilities such as fructose intolerance, fructose malabsorption, lactose intolerance and lactulose intolerance.
• The presence of Helicobacter pylori (in peptic ulcer disease) can be tested for with the urea breath test.
• Exhaled nitric oxide is a breath test that might signal airway inflammation such as in asthma.
• Breath tests for diseases have been developed for early detection of lung cancer, breast cancer, pulmonary tuberculosis and many others, to serve as an adjunct to existing medical tests. A trial will commence at Addenbrooke's Hospital in Cambridge, England to confirm the efficacy of these breath tests.^[2] Phase II and Phase III clinical studies by Menssana Research, Inc. in the United States are also under way.^[3]

• Breath diagnostics
• Breath gas analysis