Pulmonary Fibrosis – Symptoms, Causes, Stages, and Treatment

Pulmonary fibrosis is a lung disorder that occurs when the tissues in the lungs become damaged followed by scarring. Scaring results in the formation of thick and stiff tissue that makes it more difficult for the lungs to expand and relax preventing them from working properly. As pulmonary fibrosis becomes worsens, the patient becomes short of breath in a progressive manner.

The scarring linked to pulmonary fibrosis is often caused due to a combination of factors. However, in most cases, it is difficult to detect the exact cause that triggered the development of this condition. When no specific cause can be found, the condition is called idiopathic pulmonary fibrosis.

The damage caused due to pulmonary fibrosis cannot be reversed. However, medications and treatment may sometimes help to ease the symptoms and improve the patient's quality of life. In some patients, a lung transplant may be required.

Stages of pulmonary fibrosis

Stage 1: Recent diagnosis

The common early symptoms of pulmonary fibrosis include shortness of breath with physical activity, a dry cough, and fatigue. Some patients with stage 1 pulmonary fibrosis may not show any symptoms at all, or experience them only on extreme exertion, like climbing several flights of stairs.

When a patient is diagnosed with pulmonary fibrosis, the doctors may conduct a series of tests to assess the progression of the disease and determine the best treatment options.

The doctors may ask questions about the symptoms, particularly cough and shortness of breath, to assess the effect of the condition on the pulmonary functions.

Lung Function Tests can be performed to check the amount of air the lungs are able to hold, and how forcefully the patient can push the air out. The tests may also include a 6-minute walking aimed at measuring how much the patients can exercise and the extent of the shortness of breath occurring during activity.


Stage 2: The need for oxygen during activity

As pulmonary fibrosis progresses, patients experience gradual worsening of the symptoms like cough and shortness of breath. Shortness of breath occurs with physical activity during this stage, although it becomes more severe.

At this stage, the doctor may recommend the use of oxygen during activity. The need for oxygen therapy can be determined based on the oxygen saturation during activity and at rest.

Patients may be asked to monitor their oxygen saturation at home using a pulse oximeter to ensure the oxygen flow is correct. Regular monitoring is also essential for maintaining the saturation equal to or higher than 89%.

Also, although most patients have a difficulty in performing physical activity during this stage, it is still important to continue exercising as the oxygen therapy with activity is likely to help the patient feel better.

Stage 3: Need for continuous oxygen therapy

At this stage, the patient may experience shortness of breath with physical activity. The oxygen levels become extremely low, requiring the patient to use oxygen therapy even at rest.

However, they may not feel short of breath at rest.  Fatigue and cough continue to be troublesome at this stage.

Moderate physical activities and exercise with continuous oxygen therapycan help improve the patients’ energy levels and also relieve their symptoms.

Stage 4: High-flow oxygen needs

This stage is marked by advanced oxygen needs wherein a lightweight, portable oxygen machine is no longer able to meet the patient’s needs.

At this stage, the patient may need high-flow oxygen therapy with a non-portable delivery system.

You can attend our AARC Approved Respiratory CEUs to learn more about the stages of pulmonary fibrosis and the best methods of treatment at each stage to improve patient outcomes.

What are the symptoms of pulmonary fibrosis?

  • Dry cough
  • Shortness of breath
  • Unexplained weight loss
  • Fatigue
  • Pain in the muscles and joints
  • Clubbing (rounding and widening of the tips of the fingers and toes)

What are the causes of pulmonary fibrosis?

Pulmonary fibrosis occurs due to the scarring and thickening of the tissues around and between the alveoli (air sacs) in the lungs. The scarring and thickening can make it difficult for oxygen to enter the bloodstream. These abnormal changes can occur due to several factors such as long-term exposure to certain toxins, pre-existing medical conditions, side effects of some medications, and radiation therapy.

Environmental and occupational factors

Long-term exposure to toxins and pollutants in the air can cause damage to the lungs. The common toxins and pollutants known to trigger the development of pulmonary fibrosis include:

  • Asbestos fibers
  • Silica dust
  • Hard metal dust
  • Grain dust
  • Coal dust
  • Animal and bird droppings

Radiation treatment

Patients who receive radiation therapy for the treatment of cancer of the lungs or breasts often show signs of lung damage a few months,and sometimes, even years after the treatment.

The severity of the scarring in these cases may depend on factors such as:

  • The presence of other lung diseases
  • The extent of lung tissue that was exposed to radiation
  • The total amount of exposure to radiation
  • Whether radiation was combined with chemotherapy


Side effects of medications

Some drugs can cause damage to the lungs and trigger the development of pulmonary fibrosis.

These drugs include:

  • Anti-inflammatory drugs: Some anti-inflammatory drugs like rituximab can trigger the development of pulmonary fibrosis.
  • Chemotherapy drugs: The medications used to kill the abnormal cancer cells, like methotrexate and cyclophosphamide, may damage the lung tissue.
  • Antibiotics: Some antibiotics including nitrofurantoin and ethambutol can cause damage to the lungs.
  • Heart medications: Medications like amiodaronethat are used for the treatment of conditions affecting the heart may harm the lung tissue.

You can attend our AARC Approved Respiratory Therapy Webinars to learn how various factors play a role in the development of pulmonary fibrosis and what you can advise patients to prevent this condition.

Treatment of pulmonary fibrosis

The lung scarring, which results in pulmonary fibrosis, cannot be reversed. However, some treatments might help to improve the symptoms temporarily and slow down the progression of the disease.

Medications, including esbriet and nintedanib, can help to slow the progression of pulmonary fibrosis. Additionally, patients may need oxygen therapy, pulmonary rehabilitation, and even lung transplantation depending on the severity or the stage of the disease.


Pulmonary fibrosis, can progress over time and cause severe symptoms. Doctors and other healthcare professionals can attend our Respiratory Therapy Conferences to get deeper insights into the causes of pulmonary fibrous and the latest treatment methods to manage this condition.