An estimated 2%-4% of the working population could be affected by sleep disordered breathing, in particular by obstructive sleep apnea syndrome. The main symptom is excessive daytime sleepiness, caused by sleep interruptions induced by respiratory events. The level of sleepiness varies according to the severity and duration of the disease: from a slight decrease in vigilance to an almost total inability to keep alert for more than a few hours. In addition, there is an increase in cardiovascular risks and dysmetabolic disorders, which has a variable incidence in the affected population. Even less severe clinical conditions can lead to a reduction in the power of concentration, attention and working performance. The recent trend of research aims at verifying the association between risk factors and obstructive sleep apnea syndrome in order to identify those subjects at real risk, to determine the actual level of sleep-disordered breathing which should be treated and whether the less serious disturbances, so frequent in the general population, represent a real threat to health.