This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
Measuring daytime sleepiness
Feeling drowsy now and then is normal, but persistent sleepiness during the day can be a sign of a sleep disorder, and it is dangerous at the wheel or at work. The Epworth Sleepiness Scale (ESS), created by the Australian physician Murray Johns in 1991, measures it with eight questions about how likely you are to doze off in ordinary situations.
How to answer
Think about how you have felt in recent times. For each situation, rate the chance that you would doze off, not just feel tired:
- 0: would never doze
- 1: slight chance of dozing
- 2: moderate chance of dozing
- 3: high chance of dozing
If you have not been in a situation recently, imagine how it would affect you. The eight scores add up to a total from 0 to 24.
Interpreting the score
| Score | Meaning |
|---|---|
| 0 – 5 | Lower normal daytime sleepiness |
| 6 – 10 | Higher normal daytime sleepiness |
| 11 – 12 | Mild excessive daytime sleepiness |
| 13 – 15 | Moderate excessive daytime sleepiness |
| 16 – 24 | Severe excessive daytime sleepiness |
Example
Someone who has a moderate chance of dozing while reading, a high chance when lying down in the afternoon, a slight chance in front of the TV, in a meeting, as a car passenger and after lunch, and no chance while talking or stopped in traffic scores 9. That is within the normal range, toward its upper end.
Common causes of a high score
- Not enough sleep, the most common cause: most adults need 7 to 9 hours a night.
- Obstructive sleep apnea, where breathing stops repeatedly during sleep; loud snoring and observed pauses are typical. The STOP-BANG questionnaire helps screen for it.
- Narcolepsy and idiopathic hypersomnia, rarer conditions where scores are often above 16.
- Medicines such as sedating antihistamines, sleeping pills, opioids and some antidepressants.
- Depression, shift work and circadian rhythm disorders.
Limits
The ESS reflects how you perceive your sleepiness, which can differ from objective tests such as the multiple sleep latency test. People sometimes underrate their sleepiness, especially when their job or license is at stake. A score above 10, or any episode of falling asleep while driving, deserves a talk with a doctor, who may suggest a sleep study.