What is pulmonary fibrosis?

Pulmonary fibrosis (PF) describes scar tissue in the lungs. This page explains what happens in the lungs, why some people get pulmonary fibrosis, symptoms of pulmonary fibrosis and treatments.

What is pulmonary fibrosis?

You might be told by your medical team you have ‘lung scarring’ or ‘pulmonary fibrosis’. On this page, we talk about pulmonary fibrosis.

The term pulmonary fibrosis describes scar tissue in the lungs.

Pulmonary – refers to the lungs

Fibrosis – refers to scarring

Scar tissue can make it difficult for the lungs to work normally. Some people with interstitial lung disease (ILD) may develop pulmonary fibrosis.

Interstitial lung disease: a group of diseases that affect the interstitium of the lungs. The interstitium is the space in the lungs between the air sacs (alveoli) and the blood vessels. (See diagrams 2 and 3).

How do the lungs work?

Healthy lungs are spongy and stretchy so air can move in and out of them. There’s a network of tubes that carries air through the lungs. At the end of the tubes are small sacs called alveoli, surrounded by blood vessels. Oxygen and carbon dioxide move between the alveoli and the blood. The space between the alveoli and blood vessels is called the interstitium. This space contains different cells that help the lungs work properly.

What happens in the lungs when you have pulmonary fibrosis?

Scar tissue forms in the interstitium and this area becomes thicker. This makes the lungs stiff and less stretchy, which can make you feel short of breath (breathless). Several different mechanisms can cause a cough. Change to the structure of the lungs is one potential cause.

Scar tissue makes it more difficult for oxygen to move between the alveoli and the blood. Because of this, there is less oxygen available for the body to use.

Why does lung scarring happen?

We don’t know exactly what happens in the lungs when someone has pulmonary fibrosis. There’s more research looking into this. From what we have learned so far, two processes can lead to scar tissue in the lungs:


Inflammation is when something causes irritation or injury to the lungs. Some types of ILDs can cause inflammation in the lungs. These ILDs include, but are not limited to, sarcoidosis autoimmune disease-associated ILDs, and hypersensitivity pneumonitis. Inflammation can lead to scar tissue in the lungs (pulmonary fibrosis).

Lung cells age too quickly

Pulmonary fibrosis can happen when cells in the lungs age too quickly.

One of the normal functions of these cells is to repair damage. Ageing lung cells are unable to repair normally. Instead, they cause scar tissue to form. So, factors that cause lung cells to age too quickly increase the risk of pulmonary fibrosis. This includes genes (inherited from your parents), your environment (e.g. dust or smoke that your lungs have breathed in previously), and other risk factors below. Read about risk factors in the next section.

Damage to lung cells is normal. We breathe in over 10,000 litres of air each day. Air may contain dust, pollutants, viruses, bacteria or small amounts of stomach content. These can damage the delicate lining of the lungs. Cells that are lost to damage must be replaced. When a person has pulmonary fibrosis, their body is not able to replace cells as it normally would.

People around the world are working to improve the lives of those affected by pulmonary fibrosis. Sign up for our e-newsletter to learn about the amazing work happening to improve pulmonary fibrosis care, discover more about the disease and help people live well.

What causes pulmonary fibrosis?

From what we have learned so far, there is no single cause of pulmonary fibrosis. Instead, we talk about different risk factors. Risk factors can lead to inflammation or lung cells ageing too quickly. This can increase the risk of scarring.

Pulmonary fibrosis risk factors

Risk factors for pulmonary fibrosis can include:

Many people with pulmonary fibrosis have a combination of risk factors. Your medical team will try to find your risk factors. This helps them diagnose the correct type of pulmonary fibrosis.

Are there different types of pulmonary fibrosis?

Pulmonary fibrosis is a part of several different diseases. Your medical team will use information from different sources to decide your diagnosis. You can read more about this in the Diagnosis section on this page. Your medical team might say whether your disease is progressive or non-progressive. In most cases, your medical team will check if your pulmonary fibrosis changes. This is to see if your disease is progressing. It’s important to know this to help determine the right support and treatment for you.

Progressive pulmonary fibrosis

Progressive pulmonary fibrosis gets worse with time.

Non-progressive pulmonary fibrosis

Non-progressive pulmonary fibrosis is the result of a one-off event. It does not get worse over time.

Diagnosing pulmonary fibrosis

Who is involved in the diagnosis?

A doctor will diagnose pulmonary fibrosis. They are often part of a specialist ILD multi-disciplinary team (MDT).

And MDT is a team of different healthcare professionals.

Tests and scans to gather information

The healthcare professionals involved in your diagnosis will gather information in different ways. This can include:

  • Asking questions about your symptoms, and your personal and family medical history.
  • Asking questions about situations where you might have breathed in something that can irritate the lungs.
  • A physical examination. This could include listening to your breathing with a stethoscope.
  • Further tests which could include pulmonary (lung) function tests or a computerised tomography (CT)scan.

 CT scan: Combines lots of X-rays to create a more detailed image.

Sometimes, you might need other procedures to help determine the type of lung disease. These procedures might include a bronchoscopy (a camera into the lungs) or lung biopsy (taking a sample of lung tissue). The team will discuss this with you.

The information your medical team find will help them make the most likely diagnosis.

What are pulmonary fibrosis signs and symptoms?

The signs and symptoms of pulmonary fibrosis vary between individuals. They are also likely to change if the disease progresses.

Pulmonary fibrosis signs

Signs: information that healthcare professionals find.

A common sign is hearing crackles when listening to your breathing with a stethoscope. This sounds similar to Velcro being pulled apart.

Pulmonary fibrosis symptoms

Symptoms: your experience of pulmonary fibrosis.

Common symptoms can include:

  • Shortness of breath (breathlessness)
  • Dry cough
  • Tiredness (fatigue)
  • Unexplained weight loss
  • Clubbing of fingers and toes (swollen and rounded finger and toe tips – see diagram four)

Are there treatments for pulmonary fibrosis?

Currently, we can’t stop pulmonary fibrosis. However, some treatments can slow down the rate of further scarring. Other treatments can help to manage your symptoms. Not all treatments are suitable for everyone, so your medical team will discuss the best treatments for you. Some people have pulmonary fibrosis that is not progressive and might not need treatment.

Possible treatments to reduce further scarring

Options include:

Possible symptom management

Living well with pulmonary fibrosis

Everyday choices can help you live well with pulmonary fibrosis.

This might include:

Learn more about living well with pulmonary fibrosis by signing up for Insider magazine. Read stories about how people manage pulmonary fibrosis alongside their work, hobbies or family, and information from experts on living well.

Pulmonary fibrosis research

Why is pulmonary fibrosis research important?

Research studies and clinical trials help us to:

  • Learn about pulmonary fibrosis
  • Find new treatments
  • Improve clinical services and care

How to get involved in pulmonary fibrosis research

People living with pulmonary fibrosis tell us that being involved in research can be a rewarding experience. By getting involved, you can:

  • Gain a better understanding of pulmonary fibrosis
  • Build links with medical teams
  • Access new treatments
  • Help others with the disease

Learn about the exciting research happening in the UK today, and see what you can get involved in.

Or speak to your ILD team about opportunities to get involved in research.

Pulmonary fibrosis life expectancy

Reading about life expectancy can be difficult. You might want to read this information with someone you trust and can support you. The APF support line is also here for you.

What are the stages of pulmonary fibrosis?

Pulmonary fibrosis can be a progressive condition, meaning it can get worse over time. Not everyone has progressive pulmonary fibrosis. Progression can look different for everyone. Your symptoms may stay the same for a long time or get worse quickly.

How long will I live with pulmonary fibrosis?

Progressive pulmonary fibrosis is a terminal disease (sometimes also called ‘life-limiting’). This means there is currently no cure. Many people who are diagnosed with the disease will eventually die from it.

Many factors affect how long a person may live with pulmonary fibrosis, including:

  • The severity of lung scarring when you are diagnosed
  • How quickly your pulmonary fibrosis gets worse (if your disease is progressive)
  • Your other health conditions
  • If you get infections
  • Your lifestyle, e.g. if you smoke

It’s important to note that life expectancy research needs updating. It may no longer be accurate. Previous research looked at the average life expectancy of people with idiopathic pulmonary fibrosis (IPF). Life expectancy was suggested to be 3-5 years from diagnosis. However, researchers found this number before antifibrotic medications were widely used. At this time, diagnosis also took longer, and less was known about the disease.

There is also little information on the life expectancy of people with other types of pulmonary fibrosis.

There have been huge improvements in pulmonary fibrosis treatment and care. However, it’s important to acknowledge there is still work to do. This will ensure timely access to care and better treatments. Researchers are working to understand why pulmonary fibrosis happens and to find more effective treatments.

Pulmonary fibrosis support

It’s understandable to have questions or concerns about your life expectancy. Your medical team are there to support you and answer questions about your personal situation. They can also help you manage your symptoms and live a healthy lifestyle. This can improve your health and chances of living well with pulmonary fibrosis. Read more about living well in the Treatment section.

Join a support group

It’s important to remember that you are not alone. There are now over 75 pulmonary fibrosis support groups around the country. Support groups meet informally to share experiences, provide expert information and raise funds and awareness.

Call our support line

Our friendly Support line team are here for people living with pulmonary fibrosis, carers, family members and health and social care professionals. They can provide information on living with pulmonary fibrosis, emotional and practical support, and signposting to helpful services and organisations.

Find us on social media

We have an active and supportive online community ready to welcome you on Facebook, Twitter and Instagram for updates, news and connections to our online community.

Speak to a volunteer telephone befriender

Our fantastic volunteer befrienders can help you manage the changes and challenges that life with pulmonary fibrosis can bring. You'll have the opportunity to share your story and talk about your experiences. They can also signpost you to useful information and resources. Befriending is for anyone affected by pulmonary fibrosis, including family, friends and carers.

The work APF is doing for individuals and families affected by PF is great and I would like to help in any way I can.

For healthcare professionals

Find resources for your patients, opportunities to influence care pathways and much more on our Healthcare Professional Hub.

Information provided by Action for Pulmonary Fibrosis (APF) is not a substitute for professional medical advice. It’s intended as general information only. APF is not responsible for any errors or omissions or for any loss or damage suffered by users resulting from the information published on actionpf.org.

Further information for carers:

Your essential caring guide (PDF)
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