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.