The measurement of exhaled nitric oxide is a test that measures the amount of this gas on the air that is exhaled from the lungs. The procedure is very simple, providing quick and accurate results. It consists in “blowing” into a device for a specific time (6 or 10 seconds depending on age), which then measures this molecule in the exhaled air.
It is accepted that high levels of nitric oxide in the exhaled air are related to the allergic bronchial inflammation, present in some respiratory diseases, such as asthma or rhinitis. Most often, it is used to determine if a patient with respiratory symptoms has asthma and to evaluate the evolution of the disease.