What is FEV1? It is a critical measurement for those with lung disease. Find out why.
People who have a lung disease like chronic obstructive pulmonary disease (COPD), pulmonary fibrosis or emphysema know that FEV1 is an important factor in measuring their respiratory health.
However, not everyone knows why. Although FEV1 is the standard unit of measurement used by doctors, governments and insurance agencies to determine coverage, to a patient, it can feel like just another number.
With your health in mind, the Lung Institute is here to break down what this metric means for your respiratory health and diagnosis moving forward.
So what is FEV1? Here’s What You Need to Know.
What is FEV1?
To put it simply, FEV1 is the maximum amount of air you can forcefully blow out of your lungs in one second and is measured using a spirometer, an instrument that measures pulmonary air flow by having a person blow into a plastic tube.
It is used to show lung capacity and helps pulmonologists classify COPD patients into stages. The lower the FEV1, the more severe the disease.
However, the FEV1 is not used to diagnose COPD, rather, to determine the severity of it. Instead, forced vital capacity (FVC) is used to diagnose COPD, but more on that later.
What Does It Mean?
The results of the FEV1 are particularly useful when compared with current standards or expected values based on a healthy person, along with gender, height and race.
By comparing your FEV1 with the general standard, a doctor can determine the stage of your COPD—that is, how far it has progressed.
- An FEV1 of 80 > of the expected value indicates mild COPD.
- An FEV1 between 50-80 percent indicates moderate COPD.
- An FEV1 between 30-50 percent indicates severe COPD.
- An FEV1 of < 30 percent indicates very severe COPD.
The Relationship between FVC and FEV1
As you might guess, FVC and FEV1 are closely related. Your FEV1 is divided into your FVC, and the resulting percentage determines whether you have COPD.
It’s important to keep track of your FEV1 after diagnosis because it is used to determine the progression of your COPD, as well as the decline of your lung function. Staying on top of your FEV1 is critical to managing your COPD, so test yourself if you notice changes in your lung function.
We hope that you’ve found What is FEV1? Here’s What You Need to Know helpful.
As always, be sure to check with your doctor on any questions you have about your specific conditions.
Christine Kingsley, APRN is the Health and Wellness Director at the Lung Institute where she focuses on providing helpful online resources for people looking for information on various lung diseases, breathing exercises, and healthy lifestyle choices. She advocates for holistic care that involves working with your doctor to explore all options including traditional and alternative care while focusing on diet and exercise as proactive measures.