There are more obvious differences between slow-onset lung and interstitial lung disease.
(1) Different definitions: Chronic obstructive pulmonary disease is a common chronic disease characterised by chronic bronchitis and/or emphysema with airflow obstruction that can progress further to pulmonary heart disease and respiratory failure, whereas interstitial lung disease is a group of diffuse lung diseases that primarily involve the interstitial and alveolar cavities of the lungs, resulting in loss of alveolar-capillary functional units.
(2) Different etiologies: Chronic obstructive pulmonary disease is usually associated with airway and/or alveolar abnormalities caused by significant exposure to harmful particles or gases, whereas interstitial lung disease contains a wider range of diseases, most of which have an as yet unknown etiology.
(3) The symptoms are different: chronic cough can occur in slow-onset lung and can be lifelong as the disease progresses, often with a pronounced morning cough and nighttime bouts of cough or sputum, whereas interstitial lung disease often presents with a persistent dry cough.