Experiencing excessive sleepiness during the day, despite having gotten adequate sleep the previous night, could be a red flag that you have a sleep disorder such as narcolepsy.
After a night of not enough sleep, most people will likely feel drowsy the next day. And if your surroundings are dark, quiet, and relaxing enough — or if your previous night of sleep was short enough — you may even nod off inadvertently.
But if a child or teen habitually falls asleep in school, or an adult finds themself constantly dozing off at work, despite sleeping enough at night, a sleep disorder may be to blame. One such sleep problem is narcolepsy, a neurological disorder that triggers overwhelming and sudden episodes of sleep and sleepiness during the day, and potentially irregular sleep at night, too.