Cause and effect relationships between sleep disordered breathing (SDB) and illness, poorer quality of life, and public health have been largely overlooked and undertreated by healthcare providers. Obstructive sleep apnea (OSA), central sleep apnea, upper airway resistance syndrome, and obesity hypoventilation are the primary syndromes that fall under the rubric of SDB. Each of these syndromes is defined; however, OSA is the most common form of SDB, and is the focus of this article. Epidemiology, pathophysiology, behavioral manifestations, cardiovascular comorbidity, clinical evaluation, and treatment for OSA are the main topics covered. The article concludes with the role of the nurse in SDB.