Pulmonary fibrosis

What is pulmonary fibrosis?

Pulmonary fibrosis is a term that covers many different conditions that cause scar tissue to build up in your lungs.

This build-up of scar tissue, which makes your lungs stiff, is called fibrosis.

Pulmonary fibrosis is a type of interstitial lung disease (ILD). ‘Interstitial’ means the disease affects the interstitium, the lace-like network of tissue that supports the air sacs in your lungs. There are more than 200 different ILDs.

Some types of pulmonary fibrosis have an identifiable cause. But for many types, a definite cause cannot be found.

In ILDs, there can be scarring in your lungs or inflammation in your lungs. Some ILDs mostly cause scarring, some mostly cause inflammation. But often there is a combination of these processes going on. Which of these processes is dominant can determine what kind of treatment you may have.

The treatment and outlook for different types of pulmonary fibrosis vary considerably, so if you’re not sure about your diagnosis, check with your doctor or nurse for the exact name of your lung condition.

All types of pulmonary fibrosis are rare.

Although we do not always know what causes pulmonary fibrosis, we do know it is not a form of cancer or cystic fibrosis, and it is not contagious.

This information covers those seen most often:

Sarcoidosis is a relatively common type of disease that usually affects the lungs. It can sometimes cause pulmonary fibrosis but we don’t know why. Cystic fibrosis is not a type of ILD or pulmonary fibrosis.

Next: How does it affect your breathing? >

Download this information (PDF, 387KB) > Order your PF information >

Last medically reviewed: August 2016. Due for review: August 2019

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.