Sleep-related breathing disorders are a broad group of disorders that include obstructive sleep apnea, central sleep apnea, and periodic breathing disorders. This article reviews the scientific literature that links SRBD to various medical conditions including hypertension, coronary artery disease, cardiac arrhythmias, stroke, diabetes mellitus, obesity, and depression. Pathophysiologic mechanisms by which SRBD may contribute to these disorders will be discussed, as will data on the degree to which treatment of SRBD may improve these conditions.