Interstitial lung disease (ILD), characterized by inflammation and fibrosis of the lungs, is associated with progressive dyspnea and results in approximately 25 000 to 30 000 deaths in the US each year. Toby M. Maher, MD, MSc, PhD, of Keck Medicine of USC, discusses the diagnosis and management of ILD with JAMA Deputy Editor Mary McGrae McDermott, MD. Related Content: Interstitial Lung Disease