The Epworth Sleepiness Scale (ESS) is designed to measure daytime sleepiness that is measure by a short questionnaire. This can be helpful in diagnosing sleep disorders. The questionnaire asks the subject to rate their probability of falling asleep on a scale of increasing probability from 0 to 3 for 8 situations that most people engage in their daily lives though not necessarily everyday. The scores for the 8 questions are added together to obtain a single number. 0-9 is normal, 10-24 should seek medical advice.