The fractional exhaled nitric oxide (FeNO) test measures how much of a gas called nitric oxide is in the air you breathe out. When you have certain kinds of asthma, you might have high levels nitric oxide in your body. Nitric oxide is a gas produced by cells involved in the inflammation associated with allergic or eosinophilic asthma. The fractional exhaled nitric oxide (FeNO) test is used in patients with allergic or eosinophilic asthma to  determine how much lung inflammation is present and how well inhaled steroids are suppressing this inflammation.

For this test, you breathe out slowly and steadily into a tube that’s connected to a portable device. It measures the level of nitric oxide in parts per billion (PPB) in the air you slowly exhale out of your lungs. It is used to see if you have the typical inflammation associated with allergic or eosinophilic asthma during the process of establishing the diagnosis of allergic or eosinophilic asthma. Our specialists may then recheck the nitric oxide level to verify the steroid inhalers you are using are suppressing the nitric oxide level.

Call us at Allergy & Asthma Specialists where we have experience in running this test and other pulmonary function tests at 219-513-8923 to help get your lungs under control.