A validated questionnaire measuring daytime sleepiness. Developed at the Epworth Hospital, Melbourne.
How likely are you to doze off or fall asleep in each of these situations, as opposed to just feeling tired? Think about your usual way of life recently. Even if you haven't done some of these things recently, try to estimate how each would affect you.
The Epworth Sleepiness Scale (ESS) was developed in 1991 by Dr Murray Johns at the Epworth Hospital in Melbourne, Australia. It is the most widely used subjective measure of daytime sleepiness in clinical practice and sleep research.
The ESS measures "sleep propensity" — how likely you are to actually fall asleep (not just feel tired) in 8 everyday situations. This distinguishes it from fatigue questionnaires, which measure tiredness rather than sleepiness.
It is commonly used alongside the STOP-Bang questionnaire: the STOP-Bang screens for sleep apnoea risk factors, while the ESS measures the resulting daytime sleepiness.
Excessive daytime sleepiness (EDS) has many potential causes. Common ones include:
Obstructive sleep apnoea (OSA) — the most important cause to identify because it has serious health consequences and effective treatment. Use the STOP-Bang to screen.
Insufficient sleep — the most common cause overall. Most adults need 7–9 hours.
Poor sleep quality — from caffeine, alcohol, screen use, irregular schedule, or poor sleep environment.
Shift work disorder — working night or rotating shifts disrupts circadian rhythm.
Medications — antihistamines, opioids, benzodiazepines, antidepressants, and antipsychotics can cause sedation.
Medical conditions — depression, hypothyroidism, anaemia, chronic fatigue syndrome, narcolepsy.
If your ESS score is elevated, your GP can help investigate the underlying cause.