Pulmonary fibrosis

How does pulmonary fibrosis affect your breathing?

All kinds of pulmonary fibrosis result in scars in your lungs that reduce the efficiency of your breathing. Scarring makes your lungs stiffer and less elastic so they’re less able to move and take oxygen from the air you breathe.

How do you breathe?

Each time you breathe in, you draw air into your nose or mouth, down through your throat and into your windpipe. Your windpipe splits into two smaller air tubes called bronchi, which go to your lungs. The air passes down the bronchi, which divide again and again, into thousands of smaller airways called bronchioles.

The bronchioles have many small air sacs, called alveoli. Inside the air sacs, oxygen moves across paper-thin walls to the capillaries - tiny blood vessels - and into your blood. The air sacs also pick up the waste gas, carbon dioxide from your blood, ready for you to breathe it out.

Diagram of the lungs, airways, bronchioles, and air sacs

How does pulmonary fibrosis change your breathing?

If you have pulmonary fibrosis, scarring affects the air sacs in your lungs. The air sacs are supported by the interstitium, a network of supporting tissues. Scarring happens in the gaps between and around the air sacs and limits the amount of oxygen that gets into the blood.

Air sacs of the lungs in pulmonary fibrosis

As scarring increases, your lungs are less able to expand to allow you to take deep breaths and the level of oxygen in your blood can start to drop. Breathing may feel like harder work and you can feel breathless from everyday activities like walking.

Next: what causes pulmonary fibrosis? >

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Last medically reviewed: August 2019. Due for review: August 2022

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.