Screening studies have demonstrated that a substantial number of people in general population have mild to moderate sleep disorders in breathing. Many exhibit a condition with repeated episodes of apnea and hypoapea during sleep, which is frequently caused by airway obstruction, i.e., obstructive sleep apnea (OSA). OSA is common among middle-aged and elderly persons, but is seen in all age groups, and is more frequently seen in obese people. OSA is also known to increase comorbidity and mortality of cardiovascular disorders. A study of adults with chronic heart failure, who were treated with evidence based therapies, found that more than 60% had sleep apnea.. In patients with hypertension, in particular with resistant hypertension, more than 70% has OSA . OSA also contribute to poor control of blood pressure . Accordingly, treating OSA is now recommended, in most cases, by continuous positive airway pressure (CPAP) in guidelines for those cardiovascular disorders.