When you visit your doctor, he or she will ask for a detailed sleep history. The doctor may request that you fill out the Epworth Sleepiness Scale (or other sleepiness rating tools), which uses a series of short questions to gauge your degree of sleepiness. You will provide a score, based on a numbered scale, how likely it is that you would doze off in specific situations. This scale and other tools can be found below.
If your doctor suspects Narcolepsy, he or she will most likely recommend sleep studies. These sleep studies usually consist of Polysomnogram (PSG), which is an overnight stay in a sleep laboratory, followed the next day by the Multiple Sleep Latency Test (MSLT).