Obstructive sleep apnea syndrome (OSA) is the most frequent sleep disorder characterized by excessive decrease in muscle tone of the soft palate, the tongue and the posterior pharyngeal wall. It leads to airway collapse. In cases of decreased airway passage hypoventilation (hypopnea) occurs while periodic lack of airflow is called apnea. An obstructive sleep apnea syndrome is recognized as an independent cardiovascular risk factor. OSA is very common in patients with resistant hypertension. RAH is diagnosed when blood pressure remains elevated despite simultaneous use of 3 antihypertensive agents from different groups of drugs at optimal to maximum doses, including a diuretic.