Pulmonary fibrosis is a long-term disease where the lungs (pulmonary) become scarred (fibrosis). The scarring causes the part of the lung where oxygen is moved to the blood (interstitial) to become thick and stiff. If the reason or cause of the disease is unknown it is called idiopathic. Some people refer to pulmonary fibrosis as a restrictive disease because it is hard to fully expand the lungs when taking a breath in.
Pulmonary fibrosis and idiopathic pulmonary fibrosis (IPF) are a subgroup of interstitial lung diseases called interstitial pneumonia. IPF is the most common of the Interstitial Lung Diseases (ILDs), affecting 14,000 to 15,000 Canadians. It is more common in males over the age of 50.