Interstitial lung disease Interstitial lung disease Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of lung diseases affecting the interstitium (the tissue and space around the air sacs of the lungs). It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, perivascular and perilymphatic tissues. It may occur when an injury to the lungs triggers an abnormal healing response. Ordinarily, the body generates just the right amount of tissue to repair damage. But in interstitial lung disease, the repair process goes awry and the tissue around the air sacs (alveoli) becomes scarred and thickened. This makes it more difficult
Progressive disease are also referred to as degenerative diseases. Not all chronic diseases are progressive: a chronic, non-progressive disease may be referred to as a "static" condition. "Progressive disease" can also be a clinical endpoint i.e. an endpoint in a clinical trial. There are examples of slowly and rapidly progressive diseases affecting all organ systems and parts of the body. The following are some examples of rapidly and slowly progressive diseases affecting various organ systems: Progressive disease Progressive disease or progressive illness is a disease or physical ailment whose course in most cases is the worsening, growth, or spread of the disease.