What Is Spirometry?

When you have a breathing problem, one of the best ways to check lung function is through a test known as spirometry. This safe and painless process works to measure how much air you inhale along with how quickly and how much you exhale.

Our Advanced Allergy & Asthma team in Ogden, Utah, uses spirometry tests in various ways. If we recommend this test, here’s what you can expect.

Undergoing spirometry testing

Spirometry usually takes less than 15 minutes. During your test, you simply breathe into a tube that’s attached to the spirometer. This small machine measures the air you breathe and exhale, producing a graph of your airflow over time. 

In most cases, you remain seated while having spirometry testing. You should sit up straight and have both feet planted firmly on the ground. We also recommend dressing comfortably and avoiding large meals before your test, so it’s easier to breathe deeply.

Before beginning your test, we place a small clip on your nose to close your nostrils. Then, you put the spirometer tube in your mouth — forming a tight seal around it with your lips, so no air leaks out — and breathe normally for a few seconds. 

When the test begins, we ask you to take a deep breath and exhale as hard as possible into the tube for several seconds. To ensure we capture consistent results, we usually perform the test at least three times. Sometimes, we also administer a bronchodilator medication and repeat the test to see if the inhaler improves your lung function.

You may experience some dizziness or coughing during spirometry testing, but this should pass quickly.

Understanding spirometry results

A spirometer measures two critical areas of lung function: the quantity of air you can forcefully exhale and how quickly you can expel it from your lungs. The device captures this data as FVC and FEV.


Forced vital capacity, or FVC, describes how much air you can forcefully exhale after breathing as deeply as possible. Having a low FVC number indicates you have something restricting your breathing.


Forced expiratory volume, or FEV or FEV-1, measures how much air you can expel in one second. This data can help determine the severity of your breathing problem: the lower your FEV-1 measurements, the more significant the obstruction.

It’s important to note that spirometry test results vary from person to person, based on age, gender, height, and race. Before administering your test, we use these factors to predict where your “normal” values should lie. 

We consider your results normal if you score within 80% or more of this predicted value.

Putting spirometry testing to work

Spirometry testing is a valuable tool for diagnosing and managing lung conditions, such as:

If you don’t have a diagnosis of a lung condition and your spirometry results are abnormal, we could recommend additional testing to check for a breathing disorder. These screenings could include blood tests or X-rays of the chest and sinuses.

We also use spirometry testing to gauge the effectiveness of your current treatment plan. In these cases, we recommend regular testing. For individuals with well-controlled symptoms, this could mean a spirometry test every 6-12 months. However, if your condition isn’t well-managed or your medications change, we could recommend more frequent testing until we see lung function improvement.

To learn more about spirometry or schedule a test, contact Advanced Allergy & Asthma by calling or booking an appointment online today.

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