How you prepare

Check ahead of time to see whether nitric oxide testing is covered by your insurance.

Food and medications

To make sure test results are accurate, you will need to avoid the following for at least an hour before you take the test:

  • Eating and drinking

Other precautions

You will also need to avoid the following for about 24 hours before you take the test:

  • Exercise
  • Alcohol
  • Tobacco
  • Allergy shots
June 24, 2017
  1. Dweik RA, et al. An official ATS clinical practice guideline: Interpretation of exhaled nitric oxide levels (FENO) for clinical applications. American Journal of Respiratory and Critical Care Medicine. 2011;184:602.
  2. Dweik RA. Exhaled nitric oxide analysis and applications. Accessed Oct. 17, 2016.
  3. Mummadi SR, et al. Update on exhaled nitric oxide in clinical practice. Chest. 2016;149:1340.
  4. Essat M, et al. Fractional exhaled nitric oxide for the management of asthma in adults: A systematic review. European Respiratory Journal. 2016;47:751.
  5. Calhoun KH. The role of fractional exhaled nitric oxide in asthma management. Otolaryngology Clinics of North America. 2014;47:87.
  6. Li JT (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 7, 2016.