RESEARCH The perception of Obstruc

is available at the end of the articleBackground OSAHS is a common disorder in the general population but often underestimated and underdiagnosed [1]. The definition of the Obstructive Sleep Apnoea/Hypopnoea Syndrome (OSAHS) cannot be separated from an integra-tion of clinical and instrumental data. Clinically, OSAHS is characterized by excessive daytime sleepiness and/or alterations to the performance day and night snoring; from the pathophysiological point of view OSAHS is characterized by the occurrence during sleep of repeated episodes of partial or complete obstruction of the upper airways that are associated with oxygen concentration phasic reductions resulting in oxygen desaturation of arterial hemoglobin [2]. There are different degrees of obstruction of the upper airways that can determine the different respiratory events: complete obstruction (ob-structive sleep apnea) and partial obstructions (divide