A review of the evidence shows how treating sleep apnea improves quality of life by tackling daytime sleepiness.
Sleep apnea involves interruption of breathing many times during the night, because of obstruction of the airways. The standard therapy is continuous positive airway pressure (CPAP) which involves blowing pressurized air into the airways.

Researchers at Brigham and Women's Hospital in the US have reviewed 12 studies on how CPAP affects daytime sleepiness looking at 706 subjects in all. The analysis shows that CPAP has a positive effect on daytime sleepiness. This, in turn, reduces the risk of accidents as well as improving wellbeing and quality of life in those affected by sleep apnea. The next step, say the researchers, is to do a randomized prospective and large scale trial of CPAP among those with mild sleep apnea.