A spirometry test usually takes about 15 minutes and generally happens in your doctor’s office. Here’s what happens during a spirometry procedure:

1. You’ll be seated in a chair in an exam room at your doctor’s office.
2. Your doctor or a nurse places a clip on your nose to keep both nostrils closed. They also place a cup-like breathing mask around your mouth.
3. Your doctor or nurse next instructs you to take a deep breath in, hold your breath for a few seconds, and then exhale as hard as you can into the breathing mask.
4. You’ll repeat this test at least three times to make sure that your results are consistent. Your doctor or nurse may have you repeat the test more times if there is a lot of variation between your test results. They’ll take the highest value from three close test readings and use it as your result.
5. If you have evidence of a breathing disorder, your doctor might then give you an inhaled medication known as a bronchodilator to open your lungs after the first round of tests. They’ll then ask you to wait 15 minutes before doing another set of measurements. Afterward, your doctor will compare the results of the two measurements to see whether the bronchodilator helped increase your airflow. 6.
When used to monitor breathing disorders, a spirometry test is typically done once a year to once every two years to monitor changes in breathing in people with well-controlled COPD or asthma. Those with more severe breathing problems or breathing problems that aren’t well controlled are advised to have more frequent spirometry tests