Sleep in Asthma

Many patients with asthma experience nocturnal symptoms at some time in their lives and most experience them on a regular basis. In a large survey of 7729 patients with asthma,58 74% reported experiencing nocturnal cough and wheeze at least once a week. In recent years, much has been written on nocturnal asthma.3, 22, 34, 35 The most studied causes and contributing factors to exacerbations of asthma at night include circadian changes in ventilation, airway responsiveness and inflammation, mucociliary clearance, ventilatory responses to hypercapnia and hypoxia, and hormone levels. This article reviews the normal physiologic changes that affect the lung during sleep and how those changes may contribute to nocturnal asthma.