The sleepy patient

Excessive daytime sleepiness is not a disease or a disorder; it is a symptom of a sleep disorder or of another disease. In common parlance, sleepiness is synonymous with drowsiness; however, in sleep medicine, the term ‘sleepiness’ is used to describe sleep propensity, or the tendency to fall asleep in a given set of circumstances. Sleepiness can occur because of insufficient sleep, interrupted sleep or, more rarely, intrinsic sleepiness. An individual’s tendency to sleep can be assessed subjectively using the Epworth Sleepiness Scale.