Excessive sleepiness or hypersomnolence is currently defined by two main symptoms: 1) the excessive amount of sleep, defined as a prolonged period of main sleep or the presence of naps; and 2) poor quality of awakening. Excessive sleepiness was reported by 27.8%. The presence of recurrent periods of irresistible sleep in the same day was found in 13.2%, recurrent naps in the same day in 1.9%, non-restorative sleep despite a nighttime sleep of more than 9 hours (0.7%), as well as a sleep drunkenness (4.4%). Adding criteria for duration and frequency (minimum of 3 times per week and duration of at least 3 months), having social or professional impairment and psychological distress, and after excluding significant associated comorbidities, the prevalence fall to 1.5%. These very important prevalence hypersomnolence figures constitute an excellent argument to educate doctors and health authorities on the need to identify and support the excessive sleepiness disorders.