Pulmonary fibrosis is one of the more common respiratory conditions, with a large list of potential causes. Despite this, idiopathic fibrosis is the most common cause.

On the plain radiograph, this is best evidenced by an increase in interstitial markings, with or without nodularity.

Other findings on the film may point towards the potential cause like pleural plaques (asbestosis), soft tissue calcification (scleroderma) or calcified mediastinal nodes (silicosis).