“Definition of Interstitial lung disease describes a large group of disorders characterized by progressive scarring of the lung tissue between and supporting the air sacs. The scarring associated with interstitial lung disease may cause progressive lung stiffness, eventually affecting your ability to breathe and get enough oxygen into your bloodstream.
Interstitial lung disease may be broadly categorized into known and unknown causes. Common known causes include autoimmune or rheumatologic diseases, occupational and organic exposures, medications, and radiation. Interstitial lung disease of unknown cause is predominated by idiopathic pulmonary fibrosis, a specific and progressive fibrotic lung disease, followed by the idiopathic interstitial pneumonias, such as nonspecific interstitial pneumonia (NSIP), and sarcoidosis.” – mayoclinic.org