Obstructive sleep apnea osa is the most common type of sleep apnea and is characterized by repeated episodes of complete or partial obstructions of the upper airway during sleep despite the effort to breathe and is usually associated with a reduction in blood oxygen saturation in the obstructive sleep apnea hypopnea syndrome the episodes of decreased breathing are called hypopnea and. This tool is for reference purposes only. Upper Airway Stimulation For Obstructive Sleep Apnea Upper Sleep apnea also spelled sleep apnoea is a sleep disorder where a person has pauses in breathing or periods of shallow breathing during sleep. Obstructive sleep apnea risk scoring system . In the most common form this follows loud snoring. Sleep apnea is a disorder of interrupted breathing during sleep due to collapse of the airway during breathing when the pharyngeal and tongue muscles relax during sleep causing an obstructive event. Obstructive sleep apnea osa is a treatable contributor to morbidity ...