Why do I Need a Spirometry Test?

If your doctor has recommended you have a spirometry test, you’re probably wondering why you need one and what kind of test it is.

A spirometry test is among a group of breathing tests known as pulmonary function tests. This group of lung tests tell doctors how well your lungs are working. Spirometry measures how much air you breathe in and how much air you breathe out. It also measures how fast you can empty your lungs of air. Doctors use spirometry to help diagnose certain lung diseases such as chronic obstructive pulmonary disease (COPD) and asthma. The test can also help doctors evaluate the severity of your lung disease and how well you’re responding to treatment.

How Should I Prepare for a Spirometry Test?

Many times, a spirometry test can be performed at your doctor’s office or an outpatient clinic. You’ll most likely be given a list of instructions before your test to help you prepare. In general, you may see some of the following on your list of instructions:

  • Bring a copy of your medications, including their dosage, frequency and time last taken.
  • Wear loose fitting clothing that won’t inhibit your ability to take a deep breath.
  • Avoid heavy meals before your test that may impact your breathing.
  • Don’t smoke or do heavy exercise at least 6 hours before your test.
  • Refrain from drinking caffeine or alcohol the day of the test.
  • Ask your doctor if you should avoid taking breathing medication prior to your test.

Prior to the Test

A trained respiratory technician will most likely be the one performing your test. Once you arrive to the test site, the technician will explain the test and ask if you have any questions. Be sure to let the technician know if you have any questions related to the test, or if you’re not feeling your best that day. If you are feeling poorly, your technician may suggest rescheduling your test because illness may negatively impact your test results.

During the Test

spirometry test, what is a spirometry testSpirometry tests are usually administered sitting down. If you feel you can breathe better standing up, be sure to let your technician know. You’ll be given a hand-held spirometer device that has a mouthpiece on one end into which you’ll breathe during the test. Your nostrils will be clipped with a nosepiece to ensure no air leaks from your nose. It’s important to note that, although the test is usually painless, it does require a significant effort on your part to complete.

During the maneuver, you’ll be asked to inhale as deeply as you can, seal your lips around the mouthpiece and forcefully exhale as quickly and as hard as you can. You will perform this maneuver at least 3 times. Your doctor may also request that you inhale a bronchodilator medication prior to the test, so she can measure the effectiveness of this type of medication on your breathing.

Once the test is complete, test results are analyzed and then given to your doctor. You should receive your results at your follow-up appointment when you’ll have a chance to ask questions. If you don’t understand what the test results mean, it’s important that you speak up and let your doctor know. You shouldn’t leave the doctor’s office until you are satisfied with her explanation.

Are There any Risks Involved?

With the exception of mild shortness of breath or dizziness from performing the spirometry maneuver, spirometry is a relatively safe test and rarely causes any severe breathing problems. Please note: if you’ve recently had a heart attack or suffer from another heart condition, you shouldn’t perform the test.

For more information about spirometry testing, talk to your primary care provider.


Mayo Clinic. Spirometry: Overview. August 17, 2017.


Inogen Call For Support View Cart
Request a FREE Info Kit