A 31-year-old man was referred to the pulmonary outpatient clinic for evaluation of difficult breathing of 1 year in duration. He was well until a year prior to consultation when noisy breathing developed, which was followed 6 months later by progressive shortness of breath. At the time of his evaluation, he was unable to walk a full city block. He had occasional cough productive of clear sputum, with nocturnal awakening to catch his breath. He had been previously worked up and treated for asthma with no improvement in symptoms while receiving bronchodilators and corticosteroids. He denied fever, orthopnea, paroxysmal nocturnal dyspnea, chest pain, weight loss, preceding upper respiratory infection, or recent travel.