All You Need to Know about Pulmonary Fibrosis

By Dr. Hemant Kalra in Pulmonology

Dec 19 , 2023 | 10 min read


Pulmonary fibrosis, commonly called lung fibrosis, refers to the scarring (stiffening) of the lungs, and as a result, it gets difficult for the lungs to fill and expand. Hence, a person with lung fibrosis may find it difficult to breathe, which may worsen over time. There is a drop in oxygen levels; blood tissues and cells may not get the right amount of oxygen they need, which can lead to fatigue. 

Risk Factors of Pulmonary Fibrosis

  • Smoking
  • Advancing age
  • Rheumatoid arthritis
  • Genetic
  • Breathing in harmful chemicals
  • Continued exposure to dust
  • Fumes inhaled by stone cutters or polishers
  • Viral infections
  • Exposure to radiation during cancer treatment
  • Some medications, such as anticancer medicines

Common Symptoms of Pulmonary Fibrosis

Common symptoms of lung fibrosis, regardless of the underlying cause, may include:

  • Shortness of breath
  • Persistent dry cough
  • Fatigue
  • Chest discomfort or pain
  • Rapid, shallow breathing
  • Unexplained weight loss
  • Clubbing of fingers and toes
  • Bluish skin or lips (Cyanosis)

Types of Pulmonary Fibrosis

Idiopathic Pulmonary Fibrosis (IPF)

It is a progressive disease characterised by unexplained scarring of lung tissue, leading to symptoms such as chronic shortness of breath, persistent dry cough, fatigue, and chest discomfort. 

The exact cause of IPF remains unknown, but it is believed to be caused due to genetic and environmental factors. Treatment options for IPF primarily focus on symptom management and slowing the disease's progression, as there is no cure. Medications can help slow fibrosis and oxygen therapy may be required to address low oxygen levels. 

Non-Specific Interstitial Pneumonia (NSIP)

Non-Specific Interstitial Pneumonia (NSIP) is an interstitial lung disease marked by lung tissue inflammation and scarring. It often has no specific cause (idiopathic) but can be associated with autoimmune diseases such as rheumatoid arthritis. 

NSIP manifests with symptoms such as persistent dry cough, exertional shortness of breath, and reduced exercise capacity. 

Treatment involves managing inflammation and slowing fibrosis progression, typically using corticosteroids, immunosuppressive drugs, and oxygen therapy if needed. Treating any underlying autoimmune condition is also important in NSIP management.

Cryptogenic Organizing Pneumonia (COP)

Cryptogenic Organizing Pneumonia (COP), also known as bronchiolitis obliterans organising pneumonia (BOOP), is a rare lung disease characterised by sudden-onset symptoms such as cough, shortness of breath, fever, and flu-like symptoms. 

The exact cause of COP is often unknown, but it can be linked to infections, medications, autoimmune diseases, or environmental exposures. 

Treatment typically involves corticosteroids to reduce lung inflammation, with many patients experiencing significant symptom improvement. The duration of treatment varies, and some individuals may require an extended course. 

Acute Interstitial Pneumonia (AIP)

Acute Interstitial Pneumonia (AIP), also known as Hamman-Rich syndrome, is a rare and severe lung condition characterised by sudden-onset symptoms such as severe shortness of breath, cough, and fever. 

Its exact cause is often unclear, but it's associated with factors such as infections and environmental exposures. Diagnosis involves imaging studies and sometimes lung biopsies. Treatment is challenging and may require hospitalisation with mechanical ventilation and corticosteroids to manage inflammation. Survival rates are relatively low, emphasising the need for early and intensive medical intervention.


It is an inflammatory lung disease of unknown cause that forms clusters of inflammatory cells, known as granulomas, in the lung tissue. 

Treatment often involves corticosteroids or other immunosuppressive drugs to manage inflammation and symptoms, with some cases requiring long-term therapy for control. Regular monitoring by a healthcare provider is essential to assess progress and adjust treatment accordingly.

Hypersensitivity Pneumonitis

Hypersensitivity pneumonitis (HP) is an immune-mediated lung condition triggered by inhaling various environmental allergens, such as dust, mould, or bird droppings. It leads to inflammation in the air sacs of the lungs. 

The symptoms of HP include cough, shortness of breath, and fever. Chronic exposure can lead to lung fibrosis. The treatment typically involves identifying and avoiding the allergen source, along with medications to reduce inflammation.

Connective Tissue Disease-Associated Interstitial Lung Disease (CTD-ILD)

It is a group of lung disorders that occur in conjunction with autoimmune connective tissue diseases, such as rheumatoid arthritis or systemic sclerosis. In CTD-ILD, the immune system mistakenly attacks lung tissues, causing inflammation and scarring (fibrosis). 

The symptoms include breathlessness and coughing, and treatment involves addressing both the underlying connective tissue disease and lung issues with medications to suppress the immune response, reduce lung inflammation, and manage symptoms. 


It is a chronic lung disease caused by inhaling asbestos fibres. Over time, these tiny, sharp fibres can damage lung tissue, leading to scarring and reduced lung function. Asbestosis is irreversible, and severe cases can result in respiratory failure or heart problems. 

Drug-Induced Interstitial Lung Disease (DI-ILD)

Drug-Induced Interstitial Lung Disease (DI-ILD) is a condition in which certain medications can trigger inflammation and scarring (fibrosis) of the lung's interstitial tissue, impairing its ability to function properly. A wide range of drugs, including antibiotics, chemotherapy agents, and immunosuppressants, can cause DI-ILD. 

Symptoms include cough, shortness of breath, and reduced oxygen levels. Treatment involves discontinuing the offending medication and providing supportive care such as oxygen therapy or corticosteroids in severe cases. Early recognition and prompt action are essential to minimise lung damage and improve outcomes.

Radiation-Induced Lung Fibrosis

Radiation-induced lung Fibrosis is a condition where exposure to therapeutic radiation, often used in cancer treatment, leads to scarring and fibrosis in the lung tissue. This scarring can cause breathing difficulties, a persistent cough, and reduced lung function.

It typically develops months to years after radiation therapy and can impact the patient's quality of life. Management may include medications to alleviate symptoms and improve lung function, but prevention through careful radiation planning and minimising lung exposure remains essential.

Diagnosis of Pulmonary Fibrosis

The diagnosis of lung fibrosis typically involves a combination of medical history, physical examination, imaging studies, lung function tests, and sometimes, invasive procedures such as lung biopsy. Here's an overview of the diagnostic process:

Medical History and Physical Examination

The lung doctor will first take a detailed medical history, including any known risk factors, exposure to environmental toxins, and family history of lung diseases. After that, a physical examination may be conducted to assess lung sounds, oxygen saturation, and signs of respiratory distress.

Imaging Studies

  • Chest X-ray: It may reveal abnormalities such as interstitial lung markings or fibrotic changes in the lung tissue
  • High-Resolution Computed Tomography (HRCT) Scan: It is the primary imaging tool for diagnosing lung fibrosis. It provides detailed images of the lungs, helping to identify and characterize fibrotic changes

Lung Function Tests

  • Spirometry: This test measures lung function, including how much air you can inhale exhale, and how quickly you can do so. It helps assess the severity of lung impairment
  • Diffusion Capacity Test (DLCO): This test measures how efficiently oxygen moves from the lungs into the bloodstream

Blood Tests

It is used to check for markers of inflammation and autoimmune conditions, which can help identify underlying causes of lung fibrosis.


In some cases, a bronchoscopy may be done to examine the airways and collect samples from the lung for analysis. This is more often used to rule out other conditions.

Lung Biopsy

In some cases, the diagnosis may require a lung biopsy, in which a small sample of lung tissue is taken for examination. There are different biopsy methods, including surgical, transbronchial, and video-assisted thoracoscopic surgery (VATS).

Stages of Pulmonary Fibrosis

The stages of pulmonary fibrosis can vary somewhat depending on the classification system used, but generally, there are four stages:

Stage 1: Mild Fibrosis (Early Stage)

In this stage, lung scarring is limited and relatively mild, and the symptoms may be subtle or even absent. The disease may be discovered incidentally through medical imaging or lung function tests showing a slight decrease in lung capacity.

Stage 2: Moderate Fibrosis

In this stage, lung scarring becomes more apparent and widespread. Symptoms such as shortness of breath and a persistent dry cough may become noticeable. Lung function tests will typically show a more significant decrease in lung capacity compared to Stage 1.

Stage 3: Severe Fibrosis (Advanced)

In this stage, lung scarring is extensive and severe. Symptoms become more pronounced and debilitating, often significantly impacting a person's quality of life. Lung function tests reveal a substantial decrease in lung capacity, making it increasingly difficult to perform daily activities.

Stage 4: End-Stage Fibrosis

This is the most advanced stage of pulmonary fibrosis, wherein lung scarring is extensive and widespread, leaving very little healthy lung tissue. Symptoms may include extreme difficulty in breathing, severe fatigue, and a significantly reduced ability to engage in physical activities. 

Complications of Pulmonary Fibrosis

The potential complications associated with pulmonary fibrosis include:

Respiratory Failure

As pulmonary fibrosis progresses, the lung tissue becomes increasingly scarred and less functional. This can result in respiratory failure, where the lungs are unable to provide adequate oxygen to the bloodstream and remove carbon dioxide efficiently. Severe respiratory failure may require mechanical ventilation or oxygen therapy to support breathing.

Pulmonary Hypertension

The scarring and stiffening of lung tissue can increase the pressure in the pulmonary arteries, which is known as pulmonary hypertension or high blood pressure. This condition can strain the heart and eventually lead to heart failure.

Chest Infections

Weakened lung function and impaired ability to clear mucus can make individuals with pulmonary fibrosis more susceptible to infections, such as pneumonia and bronchitis. Repeated infections can exacerbate lung damage.

Increased Risk of Cancer

Some forms of pulmonary fibrosis, particularly idiopathic pulmonary fibrosis (IPF), have been associated with a slightly increased risk of developing lung cancer.

Pulmonary Embolism

Individuals with pulmonary fibrosis may be at a higher risk of developing blood clots in the pulmonary arteries, known as pulmonary embolism. This can be life-threatening if not promptly treated.

Depression and Anxiety

Dealing with a chronic and progressive lung condition like pulmonary fibrosis can lead to psychological issues, such as depression and anxiety, as individuals may struggle with the physical limitations and uncertainty associated with the disease.

Malnutrition and Weight Loss

Breathing difficulties and fatigue can make it challenging for individuals with pulmonary fibrosis to eat well and maintain a healthy weight, which can further damage their overall health.

Need for Lung Transplantation

In advanced stages of pulmonary fibrosis, when conservative treatments are no longer effective, lung transplantation may be considered as a treatment option. However, this comes with its own set of risks and complications.

Treatment of Pulmonary Fibrosis

The treatment of pulmonary fibrosis depends on its type, severity, and underlying cause of the condition. While some forms of lung fibrosis have known causes and effective treatments, others are idiopathic, meaning the cause is unknown, and management focuses on relieving symptoms and slowing progression. 

Here are some general approaches to the treatment of lung fibrosis:


  • Corticosteroids: In some cases, corticosteroid medications may be prescribed to reduce inflammation in the lungs and manage symptoms. However, they are more commonly used for certain types of lung fibrosis, such as hypersensitivity pneumonitis.  
  • Immunosuppressant: It may be used to suppress the immune response in autoimmune-related lung fibrosis.
  • Antifibrotic Drugs: For idiopathic pulmonary fibrosis (IPF), antifibrotic medications such as pirfenidone and nintedanib have been approved to slow disease progression.

Oxygen Therapy

Supplemental oxygen is often prescribed to relieve shortness of breath and improve oxygen levels in the blood.

Pulmonary Rehabilitation

This program includes exercises, education, and counselling to help individuals with lung fibrosis improve their lung function and overall well-being.

Lung Transplantation

In severe cases of lung fibrosis where other treatments are ineffective, lung transplantation may be considered.

Management of Underlying Causes

If lung fibrosis is caused by an underlying condition, such as autoimmune diseases or exposure to environmental toxins, managing the primary condition or avoiding further exposure is critical.

Life Expectancy with Pulmonary Fibrosis

The life expectancy of an individual diagnosed with pulmonary fibrosis can vary widely depending on the underlying cause of the disease, the stage of the disease at the time of diagnosis, the effectiveness of treatment, and the individual's overall health and response to treatment. 

It's important to note that while some individuals may experience a relatively stable course of the disease and extended life expectancy, others may have a more aggressive form of pulmonary fibrosis with a shorter life expectancy. There is no definitive answer to the question of life expectancy with pulmonary fibrosis.

Pulmonary Fibrosis vs COPD: Understanding the Difference

While Pulmonary Fibrosis and COPD (chronic obstructive pulmonary disease) are both respiratory conditions, which is why many people think they are the same, they have distinct characteristics. 

Lung Fibrosis

Lung fibrosis involves scarring of lung tissue, making it stiff and less elastic, which impairs the lung's ability to expand and contract. Symptoms include shortness of breath and a dry cough. It can result from various causes, including environmental exposures, medications, autoimmune diseases, and genetics. Treatment aims to manage symptoms and slow disease progression, often involving medications, oxygen therapy, and pulmonary rehabilitation.


COPD primarily arises from chronic inflammation of the airways and lung tissue, commonly due to long-term exposure to irritants such as cigarette smoke. It leads to airway obstruction, chronic cough, and excess mucus production. While there's no cure for COPD, treatments such as bronchodilators, corticosteroids, and lifestyle changes such as smoking cessation can help manage symptoms and improve the patient's quality of life. 

Both conditions require early diagnosis and individualised management strategies, and patients should work closely with healthcare providers to address their specific needs. 

If you or someone you know has been experiencing the symptoms of lung fibrosis, it is imperative to consult a doctor as soon as possible.