Exhaled Nitric Oxide Make an Appointment Ask a Question Refer Patient Exhaled nitric oxide is a simple test to measure airway inflammation. The results from this test make it easier for you and your doctor to monitor your asthma and find the best treatment plan for you. How do you get ready for the test? Please follow these directions when getting ready for this test: Do not eat, drink, or do strenuous exercise for 1 hour before the test is scheduled. Do not perform spirometry or peak flow for 1 hour before the test is scheduled. Continue to take all your medicine as you usually do, unless you have been told to withhold medications for other testing you will be doing. What is done during the test? You will be seated by the testing equipment and asked to slowly blow out. You will place a mouthpiece in your mouth. Next, you will take a deep breath in filling up your lungs. You will slowly blow the air out of your lungs. This will be repeated several times. You will have small rest times between each effort. The technician will explain the test and coach you to do it correctly. How long will the test take? The exhaled nitric oxide test often takes 10 minutes to complete. How do you get to your test? This test is performed in the Pediatric or Adult Clinics. If you have questions please call Pulmonary Physiology Services at 303.398.1530. This information has been approved by Amy Olson, MD, MSHP (August 2013).