Excessive daytime sleepiness is manifested by a desire of involuntary sleep throughout the day, in a more or less controllable manner. This results in a subjective sense of lack of attention and need to fight to resist the urge to sleep, and to maintain a sufficient level of vigilance when performing various daily activities.
This is the main symptom of narcolepsy. Unlike insomnia, patients rarely complain of daytime sleepiness. However, significantly affects the quality of life, with a decline in academic performance and professional, and can have serious consequences.