What is measured during Exhaled Nitric Oxide (FEno) testing?

In Exhaled Nitric Oxide (FEno) testing, the primary measurement taken is the concentration of nitric oxide in the exhaled breath. This test is particularly useful in assessing airway inflammation and is often utilized in patients with asthma. Elevated levels of nitric oxide in the breath can indicate inflammation in the airways, which is a hallmark of asthma and other respiratory conditions.

Nitric oxide is a signaling molecule that plays a role in various physiological processes, including vasodilation and immune responses. In the context of respiratory health, its presence in the exhaled air provides valuable insights into the inflammatory status of the airways. Monitoring FEno levels can assist healthcare providers in diagnosing and managing asthma and other pulmonary diseases more effectively.

Other measurements, such as oxygen concentration, carbon dioxide levels, and airway resistance, are important in respiratory assessment but are not the focus of FEno testing. This differentiates the test as a unique tool for understanding airway responsiveness and inflammation specifically linked to nitric oxide levels.