About idiopathic pulmonary fibrosis (IPF)

Idiopathic pulmonary fibrosis, usually shortened to IPF, is a lung condition in which the tissue around the air sacs becomes scarred and stiff. The scarring builds up over time and cannot be undone, and doctors do not know what starts it. About 30,000 people in the UK are living with IPF.

What IPF is

The name explains the condition. Idiopathic means the cause is unknown. Pulmonary means it affects the lungs. Fibrosis means scarring. In IPF, the thin tissue around the tiny air sacs deep in your lungs slowly thickens and hardens. Those air sacs are where oxygen passes into your blood, so less oxygen gets through, and your lungs also become stiffer and harder to fill.

IPF is one type of pulmonary fibrosis, not the whole of it. Lung scarring can also be caused by dust at work, by some medicines, by radiotherapy and by conditions such as rheumatoid arthritis. IPF is the diagnosis given when doctors have looked for those causes and not found one. This matters when you read statistics online, because figures for all types of pulmonary fibrosis are much larger than figures for IPF alone.

Symptoms

The two main symptoms are breathlessness and a cough.

• Breathlessness usually comes on with effort first. Many people notice it on stairs or hills before they notice it at rest.
• A dry cough that will not go away. Many people find this the hardest symptom to live with. It can be set off by cold air, strong smells, smoke or dust.
• Tiredness and, for some people, weight loss.
• Clubbing, where the fingertips become rounder and the nails curve more than usual.

When a doctor listens to your chest, they may hear fine crackles at the base of both lungs, often described as sounding like Velcro being pulled apart. Later, some people develop raised pressure in the lungs’ blood vessels and need oxygen.

Who it affects

The UK ILD Registry collected information on 5,052 people with IPF between 2013 and 2023. In that group:

• The average age at first hospital assessment was 74, and 73 in every 100 people were aged 70 or over. That average rose over the decade, from 71 in 2013 to about 76 in 2022.
• About 3 in 4 (77.8%) were men.
• About 2 in 3 (66%) were ex-smokers.
• About 3 in 4 had at least one other long-term condition, most often high blood pressure, heart disease or diabetes.

The NHS says IPF is usually diagnosed in people over 70 and is rare under 50. NICE advises doctors to consider it in anyone over 45 with the right symptoms.

What causes IPF, and what raises the risk

By definition, the cause of IPF is not known. What researchers have identified are things that make it more likely.

The strongest risk factors are getting older, being male and having smoked. Dusts at work are also linked to IPF, including metal, wood, stone and agricultural dust and asbestos.

Genes matter too. A common variant in the promoter region of the MUC5B gene (rs35705950) accounts for roughly half of the inherited risk identified so far. Rarer faults in the genes that maintain telomeres, the protective caps on the ends of chromosomes, are found in up to about 15 in 100 families where more than one person is affected, and in 1 to 3 in 100 people with no family history. In the UK registry, about 1 in 20 people (5.9%) had a parent, brother, sister or child who also had IPF. A UK consensus framework for assessing families was published in Thorax in 2026.

Having a risk factor does not mean you will get IPF, and many people with IPF have none of them.

How IPF is diagnosed in the UK

Diagnosis follows the NICE guideline CG163. It usually involves:

1. A history, an examination and blood tests to look for other causes, such as autoimmune disease.
2. Breathing tests. Spirometry measures how much air you can breathe out and how fast. A gas transfer test (DLCO) measures how well oxygen moves from your lungs into your blood.
3. A chest X-ray and then a high-resolution CT scan (HRCT), a detailed scan that shows the pattern of scarring.
4. A decision by a specialist team. In the UK, IPF should only be diagnosed by the agreement of an interstitial lung disease (ILD) multidisciplinary team: a respiratory consultant, a radiologist who reads the scans, a specialist nurse and, at some hospitals, a pathologist and a thoracic surgeon.

A lung biopsy is now uncommon. In the UK registry, 97 in 100 diagnoses were made from the HRCT scan pattern alone, and the proportion having surgical biopsy fell from about 10 in 100 in 2013 to about 4 in 100 in 2022. More than 9 in 10 people had their case discussed at a team meeting before their first specialist appointment.

What to expect

IPF gets worse over time, but how fast varies enormously from person to person.

The clearest UK figure comes from the PROFILE study, which followed 632 people diagnosed at Nottingham and the Royal Brompton between 2010 and 2017. Median survival from diagnosis was 3.7 years (95% confidence interval 3.3 to 4.0). In a separate analysis of UK primary care records from 2010 to 2019, about 4 in 10 people were alive five years after diagnosis.

Those are averages across large groups. Some people become unwell within months. Others live with IPF for more than a decade. Your team will repeat your breathing tests, usually at diagnosis and then at 6 and 12 months, because the pattern of change tells them more than any single result.

The main cause of death is an acute exacerbation, a sudden severe worsening over days or weeks, often with no clear trigger. About 14 in 100 people have one within a year of diagnosis and about 21 in 100 within three years. Survival afterwards is short, with a median of about two months.

Two medicines, pirfenidone and nintedanib, are licensed and funded on the NHS to slow the rate of decline. They do not stop or reverse scarring. See IPF treatment in the UK today.

IPF in the UK: the numbers

These are IPF figures. Figures you may see for pulmonary fibrosis as a whole are much higher because they count other causes of lung scarring as well.

Why diagnosis often takes too long

Delay is one of the most consistent findings in UK data. In the UK registry, 6 in 10 people had symptoms for more than a year before they were first seen at a specialist clinic, and nearly 4 in 10 for more than two years.

The 2025 British Thoracic Society registry report found the average wait from referral to first appointment at an English prescribing centre was 93 days, and that only 5 of 22 centres met the NHS England target of 8 weeks.

Action for Pulmonary Fibrosis surveyed 1,270 people for its 2026 State of the Nation report. About 1 in 3 had been misdiagnosed with something else first. About 1 in 5 had seen a clinician five or more times before being referred. Around half waited more than six months for a diagnosis, and fewer than 1 in 10 felt their care was well coordinated.

If you are waiting, it is reasonable to ask your GP whether you have been referred to an ILD service and when you can expect to be seen.

Where to get help

The UK support page lists helplines, local groups and practical help with benefits, oxygen and travel.

• NHS: a short overview at nhs.uk/conditions/idiopathic-pulmonary-fibrosis.
• Asthma + Lung UK: helpline 0300 222 5800, with callbacks from a nurse or physiotherapist.
• Action for Pulmonary Fibrosis: support line 01223 785 725, Monday to Friday, plus around 90 local groups across the four nations.

Neither charity can give you a diagnosis or change your treatment.