Idiopathic pulmonary fibrosis (IPF)

What is IPF?

Idiopathic pulmonary fibrosis (IPF) scars your lungs and so reduces the efficiency of your breathing.

The build-up of scar tissue is called fibrosis. Fibrosis causes the lungs to become stiffer and lose their elasticity so they’re less able to inflate and take oxygen from the air you breathe.

IPF is a progressive condition and usually gets worse over time. In some people the symptoms gradually get worse over several years. For others, the symptoms get worse more quickly.

It’s difficult to predict how IPF will progress. Sometimes when the condition has been stable, people can get sudden flare-ups of symptoms, called acute exacerbations. Everyone is different - talk to your specialist doctor about your individual situation.

How does IPF affect breathing?

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

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

The bronchioles have many small air sacs. Inside the air sacs, oxygen moves across paper-thin walls to 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.

Air sacs of the lungs in pulmonary fibrosis

If you have IPF, scarring affects the air sacs, limiting the amount of oxygen that gets into the blood. With less oxygen in the blood, you can get breathlessness from everyday activities like walking.

Who's at risk?

Our latest research suggests about 6,000 people are diagnosed with idiopathic pulmonary fibrosis (IPF) every year in the UK. 

Men are more likely to have IPF. IPF can affect people of all ages, but around 85% of diagnoses are made in people over 70.

Next: Causes of IPF >

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Last medically reviewed: September 2016. Due for review: September 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.