Pulmonary fibrosis - Association pulmonaire du Québec
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Pulmonary fibrosis

Pulmonary fibrosis is a chronic disease whose causes are very varied. It causes inflammation and scarring of the lungs. Many diseases can cause pulmonary fibrosis, but in half of the cases the cause remains unknown.

Pulmonary fibrosis is a complicated, chronic illness that can derive from many different causes. There are over 140 known causes or associations with pulmonary fibrosis. It appears that the lung is reacting to some insult by developing inflammation and subsequent fibrosis. The nature of the initial insult is not always known and although we sometimes say that pulmonary fibrosis is due to a given disease, we may not often know the specific causes of those diseases either.

  • When the cause is not known, the condition is called idiopathic (of unknown origin) pulmonary fibrosis.
  • When the cause can be identified, it may be called Interstitial pulmonary fibrosis, fibrosing alveolitis, intersititial pneumonitis or “Hamman-Rich syndrome”.


Many jobs, particularly those that involve working with asbestos, ground stone, or metal dust, can cause pulmonary fibrosis. The small particles are inhaled, damage the alveoli, and cause fibrosis. Some organic substances, such as moldy hay can also initiate pulmonary fibrosis. Asbestosis, silicosis, sarcoidosis and “farmer’s lung” can also cause pulmonary fibrosis.

Some other diseases may be responsible for pulmonary fibrosis:

  • tuberculosis and viral infections,
  • diabetes,
  • rheumatoid arthritis,
  • lupus (in rare cases).

Certain strong medicines, poisons, industrial gases and chest radiotherapy may have the undesirable side effect of causing pulmonary fibrosis.

Patients of any age, either men or women, may develop pulmonary fibrosis, and there appears to be no sexual, racial, or geographical predilection. The condition is usually diagnosed when the patient is between 40 and 70 years of age. Also, children may develop idiopathic pulmonary fibrosis. It can be a mild or a severe and degenerative disease.

Persons at risk

People at risk of developing pulmonary fibrosis are those who either breathe or have been exposed to:

  • Inorganic dust (eg silicosis, asbestosis, beryllium, etc.)
  • Organic agents (eg, moldy hay, bird feces, etc.)
  • Toxic gases (eg aerosols, vapors, smoke, etc.)
  • Radiation (eg radiotherapy, etc.)
  • Some drugs and illegal drugs

Signs and symptoms

Generally, this disease occurs around the age of 50 years. Two signs usually appear at the onset of the disease, making diagnosis difficult since they are found in several other lung diseases:

  • Unusual shortness of breath during physical exertion that becomes permanent
  • A dry cough

These two symptoms signal the onset of fibrosis, but others may be present :

  • Loss of endurance during physical or daily activities
  • Loss of appetite
  • Tiredness
  • Weight Loss
  • A diffuse pain in the chest

Thereafter :

  • A shortness of breath without physical effort, eating, talking or simply resting
  • Cyanosis (bluish coloration of the lips, nails and sometimes of the skin, caused by insufficient oxygenation of the tissues)
  • A distortion of the fingers (digital hippocratism)

Pulmonary fibrosis can result in serious complications including pulmonary hypertension, increased pressure in the lung’s blood vessels. The risks of heart attack and stroke are also increased, as are the risks of respiratory infections.


A chest x-ray may give some clues. Pulmonary function tests, which reveal the efficiency of a patient’s breathing mechanism, may give other indications. Bronchoalveolar lavage (a test which permits removal and examination of cells in the lower respiratory tract) is sometimes used for diagnosis. At some point, a lung biopsy may be performed so that cells in and around the alveoli can be examined.


If one of the known causes of pulmonary fibrosis exists, then treatment of that underlying disease or removal of the patient from the environment causing the disease can be effective. Many times treatment is limited only to treating the inflammatory response that occurs in the lungs. This is done in the hope that stopping the inflammation will prevent the laying down of scar tissue or fibrosis in the lungs and thus stop the progression of the disease. Other drugs have been tried but convincing evidence of their efficacy is lacking.

Although drug therapy of pulmonary fibrosis may not always be successful, there is much that can be done in the way of supportive therapy that will ease the breathlessness that accompanies this condition. Rehabilitation and education programmes can help considerably in teaching patients how to breathe more efficiently and to perform their activities of daily living with less breathlessness. Sometimes supplemental oxygen therapy is required in order to treat breathlessness. Early treatment of chest infections is required. Smoking must be discontinued, as the effects of tobacco will aggravate the shortness of breath.

Tips and prevention

Here are some tips that could improve your quality of life:

  • Quit smoking
  • Promptly treat respiratory infections
  • Adopt a diet rich in fruits and vegetables
  • Getting vaccinated against influenza and pneumococcus
  • Stay active. Inform yourself to take part in a pulmonary rehabilitation program

Did you know that

The Quebec Lung Association offers direct services to the population. For more information, visit our Patient Resources section.