Obstructive sleep apnea and cardiovascular risk.

Obstructive sleep apnea (OSA) is a form of sleep disordered breathing characterized by episodes of apnea (during sleep) lasting at least 10 seconds per episode. The apneic periods are associated with arterial hypoxemia and disruption of normal sleep as a result of awakenings. It is increasingly being recognized that OSA is a public health hazard and there is increasing evidence that it is associated with an increase in morbidity (and possibly mortality).