ConditionLungs & breathing
Pulmonary Fibrosis
Pulmonary fibrosis is scarring and thickening of the lung tissue around the air sacs, which makes the lungs stiff and reduces how well oxygen passes into the blood. It causes gradually worsening shortness of breath, a dry cough and fatigue. It has many causes, including autoimmune diseases, workplace dusts, some medicines and radiation, but the most common form, idiopathic pulmonary fibrosis (IPF), has no known cause. Scarring cannot be reversed, but antifibrotic medicines slow it, and pulmonary rehabilitation, oxygen and lung transplant help.
Also called: Lung fibrosis, scarring of the lungs, fibrotic interstitial lung disease, idiopathic pulmonary fibrosis (IPF)
At a glance
- What it is
- Scarring of the lung tissue that stiffens the lungs and impairs oxygen transfer.
- Most common type
- Idiopathic pulmonary fibrosis (IPF), mostly in people over 60, more often men and former smokers.
- Other causes
- Autoimmune disease (scleroderma, rheumatoid arthritis), hypersensitivity pneumonitis, asbestos and silica, drugs, radiation.
- Symptoms
- Progressive breathlessness on exertion, dry cough, fatigue, finger clubbing, crackles in the lungs.
- Treatment
- Antifibrotics (nintedanib, pirfenidone, nerandomilast), oxygen, pulmonary rehab, treating the cause, lung transplant.
When to get help
Call 911 or go to the ER
- Sudden severe worsening of breathlessness, blue lips, or confusion. Call 911 or your local emergency number
- Chest pain with sudden breathlessness
See a doctor within a day or two
- Breathlessness getting noticeably worse over days to weeks, or new fever with worsening cough (possible acute exacerbation or infection)
- Oxygen saturation on a home monitor below the level your team advised
Book a routine appointment
- Breathlessness when walking or climbing stairs that has been increasing for months
- A dry cough lasting more than 8 weeks
- Finger clubbing (rounded, enlarged fingertips)
- Crackles heard in the lungs at a check-up, or lung scarring found on a scan
What happens in pulmonary fibrosis
The lungs contain millions of tiny air sacs (alveoli) surrounded by thin walls (the interstitium) where oxygen passes into the blood. In pulmonary fibrosis, repeated injury to these walls triggers abnormal healing. Instead of repairing normally, the tissue lays down excess collagen and scar tissue. The walls thicken and stiffen, so the lungs cannot expand fully and oxygen transfer is impaired.
Pulmonary fibrosis is one type of interstitial lung disease (ILD), a group of more than 200 conditions affecting the lung interstitium.
Causes
| Category | Examples |
|---|---|
| Idiopathic | Idiopathic pulmonary fibrosis (no known cause) |
| Autoimmune (connective tissue disease) | Systemic sclerosis, rheumatoid arthritis, myositis, Sjögren's, lupus |
| Inhaled exposures | Hypersensitivity pneumonitis (birds, molds, feather bedding), asbestosis, silicosis, coal dust, metal dusts |
| Medicines | Amiodarone, nitrofurantoin, methotrexate, bleomycin, some immunotherapies |
| Radiation | Chest radiotherapy for lung or breast cancer |
| Other | Sarcoidosis, familial pulmonary fibrosis (telomere gene variants) |
Risk factors for IPF
- age over 60
- male sex
- cigarette smoking (current or former)
- family history
- gastroesophageal reflux
- occupational exposures (wood and metal dust, farming)
Symptoms
- shortness of breath, first with exertion and gradually with less activity
- a persistent dry, hacking cough
- fatigue and weakness
- unintended weight loss
- aching muscles and joints
- finger clubbing
- in advanced disease: low oxygen levels, swelling of legs from right heart strain (pulmonary hypertension)
Symptoms develop slowly, so people often attribute them to aging or being out of shape.
Diagnosis
- Listening to the lungs: fine "Velcro-like" crackles at the bases are typical.
- High-resolution CT (HRCT) scan: the key test. A "usual interstitial pneumonia" (UIP) pattern with honeycombing at the bases strongly suggests IPF.
- Pulmonary function tests: reduced lung volumes (restriction) and reduced gas transfer (DLCO).
- Six-minute walk test with oxygen monitoring.
- Blood tests for autoimmune disease.
- Exposure history for birds, molds, dusts and medicines.
- Bronchoscopy with lavage or lung biopsy (cryobiopsy or surgical) when the diagnosis is uncertain.
- Multidisciplinary discussion between lung specialists, radiologists and pathologists to reach the diagnosis.
Treatment
Antifibrotic medicines
- Nintedanib and pirfenidone slow the decline in lung function by about half in IPF. Nintedanib is also approved for progressive fibrosis from other causes and scleroderma-related ILD.
- Nerandomilast was approved in 2025 for IPF.
- Side effects include diarrhea, nausea and liver changes (nintedanib), and nausea, sun sensitivity and rash (pirfenidone).
Treat the cause
- remove exposures (birds, molds, dusts) in hypersensitivity pneumonitis
- stop causative medicines
- immune-suppressing treatment for autoimmune ILD
Supportive care
- Pulmonary rehabilitation: exercise training and education that improve breathlessness, exercise capacity and quality of life
- Oxygen therapy for low oxygen levels at rest, with exertion or during sleep
- Vaccinations: flu, pneumococcal, COVID-19 and RSV
- Stop smoking
- Treat reflux if symptomatic
- Cough control
- Palliative care for symptom relief and planning
Lung transplant
For suitable patients with progressive disease, lung transplant can extend life and improve quality of life. Early referral for evaluation is recommended.
Complications
- acute exacerbations: sudden worsening, often with high mortality
- respiratory failure
- pulmonary hypertension and right heart failure
- lung cancer (higher risk in IPF)
- blood clots and infections
Outlook
The course varies. IPF has historically had a median survival of about 3 to 5 years after diagnosis, though antifibrotic treatment slows decline and many people live longer. Fibrosis from other causes may stabilize, especially if the trigger is removed or treated.
Frequently asked questions
What are the first signs of pulmonary fibrosis?
The first signs are usually shortness of breath during activity and a dry cough that does not go away. They develop gradually over months, so they are often mistaken for aging or being unfit. Crackles in the lungs may be heard by a doctor.
What causes pulmonary fibrosis?
Causes include autoimmune diseases, inhaled dusts and molds, certain medicines and chest radiation. Often no cause is found, which is called idiopathic pulmonary fibrosis. Age, smoking, family history and reflux increase risk.
Can pulmonary fibrosis be reversed?
Established scarring cannot be reversed. Treatments such as antifibrotic medicines slow its progression, and removing triggers can stop some types from worsening. Pulmonary rehabilitation and oxygen improve symptoms and quality of life.
What is the life expectancy with pulmonary fibrosis?
It varies widely by type and how quickly it progresses. IPF historically had a median survival of 3 to 5 years, but antifibrotic drugs slow decline and many live longer. Your specialist can give a more personal outlook based on tests over time.
Sources
This guide was written from current patient and clinical guidance, including:
- American Thoracic Society, ERS, JRS and ALAT: Idiopathic pulmonary fibrosis and progressive pulmonary fibrosis clinical practice guideline
- Pulmonary Fibrosis Foundation: About pulmonary fibrosis
- NHLBI: Idiopathic pulmonary fibrosis
- American Lung Association: Pulmonary fibrosis
- MedlinePlus: Pulmonary fibrosis