Idiopathic pulmonary fibrosis (IPF) is a type of chronic lung disease characterized by a progressive and irreversible decline in lung function. Symptoms typically include gradual onset of shortness of breath and a dry cough. Other changes may include feeling tired and nail clubbing. Complications may include pulmonary hypertension, heart failure, pneumonia, or pulmonary embolism.The cause is unknown. Risk factors include cigarette smoking, certain viral infections, and a family history of the condition. The underlying mechanism involves scarring of the lungs. Diagnosis requires ruling out other potential causes and may be supported by a CT scan or lung biopsy. It is a type of interstitial lung disease (ILD).People often benefit from pulmonary rehabilitation and supplemental oxygen. Certain medications like pirfenidone or nintedanib may slow the progression of the disease. Lung transplantation may also be an option.About 5 million people are affected globally. The disease newly occurs in about 12 per 100,000 people per year. Those in their 60s and 70s are most commonly affected. Males are affected more often than females. Average life expectancy following diagnosis is about four years.