IPF and
Lung Function

Home Learn About IPF IPF and Lung Function

If you’ve been diagnosed with idiopathic pulmonary fibrosis (IPF), you may feel overwhelmed and confused by this complex disease. We’re here to help.

On this page, you’ll learn how the lungs work and how IPF affects lung function. Read on to learn more.


Oxygen is inhaled through the mouth or nose and travels into the lungs. Once inside the lungs, oxygen passes through tiny air sacs, called alveoli, before being released into the bloodstream and traveling to the heart. From there, the oxygen-rich blood is pumped throughout the body.

While oxygen moves into the blood in the alveoli, carbon dioxide, which is a waste product from the cells, passes from the bloodstream and into the alveoli so that it can be exhaled from the body.


In a person with IPF, scar tissue forms in the walls of the alveoli in the lungs. The stiff scar tissue makes it harder for oxygen to pass through the alveoli walls and into the bloodstream and for carbon dioxide to be removed.

How IPF Affects the Lungs

Once this scarring occurs, it cannot be reversed, causing permanent loss of lung function.

How IPF Affects the Lungs

Watch this educational video to learn more about how IPF affects the lungs.

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  • IPF is a serious and progressive lung disease that may impact both lungs and worsens over time, causing irreversible and permanent damage. Healthy lungs work by expanding to take in oxygen, which then travels through your bloodstream to your entire body.

  • IPF affects the lungs, causing them to lose the ability to expand fully and therefore take in less oxygen, which causes shortness of breath. Everyone experiences decline in lung function as they age, but patients with IPF lose lung function at a rate of 3 to 4 times more.

  • Some patients experience a severe and sudden worsening of their symptoms called an acute exacerbation. These events can leave patients with less lung function and is a possible sign that IPF is getting worse.

  • OFEV is an FDA-approved medicine that helps slow lung function decline in patients with IPF. In 3 out of 3 medical studies, taking OFEV slowed the decline in lung function by approximately 50%. In 2 out of 3 medical studies, OFEV significantly reduced the risk of a first acute exacerbation.

Want more information about how IPF progresses?



One of the ways doctors will keep track of IPF progression and how it’s affecting lung function is by testing forced vital capacity (FVC). Here’s what you need to know about FVC:

Lung Function Test

This test is often referred to as a pulmonary or lung function test and is measured using a spirometer.

Deep Breath and Blow into Spirometer

For this test, you take your deepest breath, and then blow as hard and as long as possible into the spirometer.

If your FVC score decreases over time, this is a sign that your IPF is getting worse and—if you’re not already on treatment—it is time to speak to your doctor about beginning treatment.

It’s important to remember, however, that even if your FVC score isn’t decreasing, IPF is still a progressive disease, which is why treatment discussions with your doctor are important.

Quick Fact: On average, people with IPF lose 3 to 4 times (150 to 200 mL measured by FVC) more lung function each year than those without IPF.