Causes of Pulmonary Fibrosis

Reading time: 2 min

The mechanisms that trigger these diseases are not the same as in the development of each one of them. Diffuse interstitial lung diseases (DILD) can occur without a known cause, which is called idiopathic, or due to other causes such as, for example:  

Woman with spots on her face typical of Lupus or cutaneous erythematosus.

Autoimmune diseases. In autoimmune diseases like rheumatoid arthritis, lupus, vasculitis, scleroderma… the immune system attacks its own respiratory system. 

Duster and dust

Inhalation of foreign substances by the body, like certain types of dust, fungi, or contact with birds, which produce inflammation of the lungs that finally ends up as fibrosis (pneumonitis due to chronic hypersensitivity). 

Green, blue and white striped tablets

Drugs, like sulphamides, nitrofurantoin, amiodarone, methotrexate, some monoclonal antibodies, or some types of chemotherapy, like bleomycin, which can initially inflame the lung (drug-induced-pneumonitis). 

Radiotherapy symbol

Radiotherapy, in some areas of the chest. 

Factory with a smoky, polluting chimney

Occupational exposure, (to work exposed to asbestos, coal dust, cotton dust, wood dust, silica dust, dust from hard metals, etc.), that may lead to inflammation of the lung and that, after a prolonged time, can lead to lung fibrosis. 

Furthermore, it should be taken into account that smoking increases the risk of developing any diffuse interstitial lung diseases and could worsen the prognosis of the disease. 

Risk factors

Some factors that increase the risk of developing a fibrosing interstitial lung idiopathic diseases are: 

DNA molecule or helix

Family history or genetic predisposition. Around 5% of IPF can be familial.


Smoking. Some fibrosing DILD are more common in smokers, such as IPF, or the combination of pulmonary fibrosis-emphysema. 

Man and woman

Age and gender. Some fibrosing DILD associated with autoimmune diseases are more common in women between 30-40 years-old. On the other hand, the majority of patients with IPF are men over 55 years-old. 

Factory with a smoky, polluting chimney

Type of work, hobbies, home environment. The duration of any exposures should be taken into account, and whether breathing protection has been used (masks).  

Intravenous chemotherapy bag

Previous treatments, such as chemotherapy or radiotherapy. There are many types of drugs capable of triggering a fibrosing DILD. 

Woman with spots on her face typical of Lupus or cutaneous erythematosus.

Previous diseases. Some autoimmune diseases predispose the development of some fibrosing DILDs. 

Substantiated information by:

Fernanda Hernandez Gonzalez
Jacobo Sellarés Torres
Joel Francesqui
Sandra Cuerpo Cardeñosa
Xavier Alsina Restoy

Published: 9 June 2020
Updated: 9 June 2020

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