Idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a specific form of progressive, chronic fibrosing interstitial lung disease occurring primarily in older adults and limited to the lungs. The prognosis is dire, with half of all patients progressing to death from respiratory failure within 3 to 5 years from initial diagnosis. The pathogenesis of IPF is complex and incompletely understood, and the natural history of this disease is variable and unpredictable.