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Spirometry is a common and effective diagnostic test that can easily be done in your doctor's office or at a nearby hospital or clinic. You will be asked to take in a big breath, and then blow as hard and long as you can into a machine. The machine measures how much air you can blow out from your lungs and how fast you can blow it out. Spirometry is the most reliable way to test your lungs for COPD (chronic obstructive pulmonary disease) and asthma.

Your doctor may call spirometry by another name including: pulmonary function test (PFT) or lung function test.

Why is spirometry important?

Spirometry can be used to diagnose and manage many different types of lung disease. If you have questions or concerns about your lung health, talk to you doctor about spirometry.

The earlier spirometry is done, the earlier lung disease can be detected and treated. There are many treatments to reduce symptoms, to prevent lung disease from becoming worse, decrease flare-ups (exacerbations) and improve your day-to-day life.

Who should have spirometry testing?

  • People with asthma
  • Spirometry is an important diagnosis and management tool for people with asthma. If you have asthma and never had a spirometry test, please talk to your doctor about spirometry.
  • Smokers and former smokers
  • If you are over 40 and smoke or used to smoke, you may have COPD. Take this quick test to screen for symptoms of COPD.

What happens in a spirometry test?

Spirometry is a painless test that can often be done in your doctor’s office or in a nearby clinic. The entire test usually takes less than 10 minutes, although sometimes it is repeated after taking a puffer medication.

You will be asked to breathe through a mouthpiece while wearing a nose clip. The tester will coach you to take in as big a breath as possible. You will then blast the air out as fast as you can until your lungs are completely empty. You may then be asked to take another deep breath in again. You will do this three times or more to make sure the results are accurate. You may also be given a medication to breathe in. The test would then be repeated to show if your lungs have responded to the medication.

How to prepare for the test:

  • Do not smoke for one hour before test
  • Do not drink alcohol within four hours of test
  • Do not eat a large meal within two hours of test
  • Please wear loose clothing
  • Do not perform vigorous exercise within 30 minutes of test
  • If you are on puffer medications, you may be asked to not take them for a few hours before spirometry. Ask your doctor (or the center performing the test) beforehand if this applies to you.

What does spirometry measure?

  • Spirometry tells your doctor if your lungs are functioning normally. It does this through different breathing measurements, some of the most common measurements include:
  • Forced Vital Capacity (FVC) – The largest amount of air that you can blow out after you take your biggest breath in.
  • Forced Expiratory Volume (FEV1) – The amount of air you can blow out of your lungs in the first second.
  • If the amount of air you blow out in the first second is low, you might have a lung disease such as asthma or COPD.
  • If you have already been diagnosed with asthma or COPD, spirometry can be useful to determine if your current treatment is working.

So show your lungs some love. Talk to your doctor about spirometry.