Over the past decade, more and more evidence has been emerging to link cardiovascular diseases and sleep. The most notorious association has been with obstructive sleep apnea (OSA). Indeed, OSA has been linked to a greater risk of elevated blood pressure, heart attacks, heart failure, abnormal heart rhythm and strokes. The low oxygen levels that occur during sleep in patients with OSA are thought to be responsible for most of the cardiovascular consequences. Treatment with CPAP has been shown to improve blood pressure and reduce mortality from heart attacks but long term studies are still lacking. Central sleep apnea, another sleep disorder, is linked to congestive heart failure and may also signal increased mortality. CPAP treatment is promising. Other sleep disorders such as insomnia, long and short sleep time, restless leg syndrome and circadian rhythm disorders have also been associated with higher cardiovascular risk.