In the past 5 years several epidemiologic studies have demonstrated that sleep-related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of repetitive episodes of hypoxia, hypercapnea, arousals, and a striking surge in sympathetic excitation, and altered baroreflex control during sleep. Obstructive sleep apnea (OSA) may lead to the cardiac arrhythmias and myocardial ischemia and it is a possible risk factor for stroke. We confirmed that nasal CPAP has been shown to lower blood pressure in some hypertensive OSA patients. Early recognition and treatment of sleep-apnea may improve cardiovascular function.