A spirometry test requires you to breathe into a tube attached to a machine called a spirometer. Before you do the test, a nurse, a technician or your doctor will give you specific instructions. Listen carefully and ask questions if something is not clear. Doing the test correctly is necessary for accurate and meaningful results.
In general, you can expect the following during a spirometry test:
- You'll likely be seated during the test.
- A clip will be placed on your nose to keep your nostrils closed.
- You will take a deep breath and breathe out as hard as you can for several seconds into the tube. It's important that your lips create a seal around the tube, so that no air leaks out.
- You'll need to do the test at least three times to make sure your results are relatively consistent. If there is too much variation among the three outcomes, you may need to repeat the test again. The highest value among three close test results is used as the final result.
- The entire process usually takes less than 15 minutes.
Your doctor may give you an inhaled medication to open your lungs (bronchodilator) after the initial round of tests. You'll need to wait 15 minutes and then do another set of measurements. Your doctor then can compare the results of the two measurements to see whether the bronchodilator improved your airflow.
Aug. 17, 2017
- Mason RJ, et al. Pulmonary function testing. In: Murray and Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed May 2, 2017.
- Pulmonary function tests. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/healthtopics/topics/lft. Accessed April 27, 2017.
- McCormack M, et al. Office spirometry. https://www.uptodate.com/contents/search. Accessed April 27, 2017.