To diagnose excessive sleepiness, a sleep specialist will ask a number of questions about your sleep schedule and sleep habits. He or she will also ask how likely you are to fall asleep in various scenarios – for example, while sitting in a theatre or riding as the passenger in a car. This assessment is often given in the form of a questionnaire called the Epworth Sleepiness Scale. In some cases it may be recommended that you do a multiple sleep latency test, which measures your tendency to fall asleep during the day. In the multiple sleep latency test, you are asked to lie down in a quiet environment and the time it takes for you to fall asleep is measured. This may be repeated multiple times during the day.
Obstructive sleep apnea is diagnosed through gathering a health history, assessing your daytime sleepiness, and performing a sleep study . In a sleep study, information about your sleep is gathered overnight, either at home or in a sleep lab.