Health Topics

Pulmonary Function Test: Exhaled Nitric Oxide (eNO)

The Division of Pulmonary Medicine at Cincinnati Children's performs exhaled nitric oxide (eNO) tests.  

Exhaled nitric oxide (eNO) is used to measure inflammation in the airway. Nitric oxide (eNO) is a gas that is found in the lungs and is produced when we breathe.

eNO levels may be higher in children who have asthma. When airways are inflamed or swollen, higher levels of NO are made.

This test can help your doctor confirm a diagnosis of asthma. eNO levels are sometimes measured to see how well a treatment or medication is working for your child.

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Test Procedure

Time of the Test

Preparing Your Child for the Test

Possible Side Effects


Last Updated: 08/2013