Idiopathic pulmonary fibrosis is the progressive parenchymal scarring & loss of pulmonary function due to unidentifiable cause of lung injury.

It is a specific form of chronic fibrosing interstitial pneumonia with the histopathologic characteristics of usual interstitial pneumonia.

Approximately 5% of patients are asymptomatic. Common signs and symptoms are exertional dyspnea, nonproductive cough, finger clubbing and bilateral inspiratory crackles.