Obstructive Sleep Apnoea At a Glance : LAP Lambert Academic Publishing : 9786139934485 : 6139934486 : 21 Feb 2019 : Obstructive sleep Apnoea (OSA) was first described in medical literature in 1965. Obstructive sleep apnoea syndrome (OSAS) is characterized by recurrent episodes of partial or complete upper airway obstruction during sleep. This manifests as a reduction (hypopnoea) or complete cessation (apnoea) of airflow despite ongoing inspiratory efforts resulting in oxygen desaturation and arousals. Daytime symptoms such as excessive sleepiness are thought to be related to sleep disruption (repetitive arousals) and possibly to recurrent hypoxemia. It is a relatively common condition occurring in 2 to 4 % of males and 1 to 2 % of females in middle age. There are many causes of OSA like obesity, age, enlarged tonsils, narrower natural throat form, smoking and alcohol use etc.