Excessive daytime sleepiness (EDS)
Excessive daytime sleepiness (EDS) is characterized by persistent sleepiness, and often a general lack of energy, even after apparently adequate night time sleep. EDS is a symptom of one of the two forms of the sleep disorder hypersomnia, the other being prolonged nighttime sleep.
Some persons with EDS, including those with narcolepsy, are compelled to nap repeatedly during the day; fighting off increasingly strong urges to sleep during inappropriate times such as while driving, while at work, during a meal, or in conversations. As the compulsion to sleep intensifies, the ability to complete tasks sharply diminishes, often mimicking the appearance of intoxication.