What is Forced Expiratory Volume?

Learn about This Lung Function Test

Doctor explaining lung function test to young boy in clinic
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Do you know how strong your lungs are? Forced expiratory volume in one second, or FEV1, is a marker used to measure lung function, and can help you monitor your COPD over time. Here's what to know about FEV1, how's it's measured and what it means for your COPD.

What is Forced Expiratory Volume?

FEV1 is the amount of air that can be forcibly exhaled from the lungs in the first second of a forced exhalation.

It is one of the measures doctors use to determine your lung function. Because COPD causes the air in your lungs to be exhaled at a slower rate and in smaller amounts compared to a healthy person without COPD, measuring how well you can forcibly exhale air can help determine the presence of COPD and disease severity.

Measuring FEV1

In order to determine your FEV1, your doctor will conduct a spirometry test. On top of FEV1, your doctor will also often check your vital capacity, peak expiratory flow rate, forced expiratory flow and other markers of how your lungs are functioning. For more on those measures, read about Pulmonary Function Tests.

Your test results will be compared with predicted "normal: values that use demographics such as age, gender, body size and ethnicity as a method of standardization. This gives doctors a way to compare your tests results with those from people with healthy lungs.

Spirometry tests are typically measured before and after the administration of a bronchodilator to see how treatment is working and if your COPD symptoms have improved at all.

How to Improve FEV1

One of the most commonly prescribed ways to increase FEV1 in people with COPD is with the use of a bronchodilator inhaler.

There are many kinds of bronchodilators, including long-acting and short-acting beta-agonists, anticholinergics, methylxanthines and combination drugs. Talk to your doctor about which bronchodilator is right for you.

Lifestyle factors can play a role in improving FEV1. Smoking is the most important risk factor for developing COPD. As such, quitting smoking is very important for slowing down the accelerated decline in FEV1 caused by smoking and COPD.

In addition, exercise, which has been found to improve COPD symptoms by helping your body use oxygen more efficiently, is also beneficial for improving FEV1, research suggests. Read The Best Exercises for COPD Patients before getting started with a new exercise plan.

If your FEV1 doesn't measure up, there is hope. Check out these resources for more information about spirometry tests and diagnosing COPD:

Diagnosis of COPD

Factors Associated with COPD Life Expectancy

Factors That May Influence Your Spirometry Results

How Do I Interpret My Spirometry Test?


Fatima, S., Rehman, R., & Khan, Y. (2013, March 1). Physical activity and its effect on forced expiratory volume. Retrieved January 19, 2016

Willemse, B., Postma, D., Timens, W., & Hacken, N. (2004). The impact of smoking cessation on respiratory symptoms, lung function, airway hyperresponsiveness and inflammation. European Respiratory Journal, 464-476. doi:10.1183/09031936.04.00012704

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