The Epworth Sleepiness Scale measures something other than insomnia
Epworth measures the tendency to doze off in everyday situations, not insomnia. Why people with insomnia usually score low, and what a score of 10 means.
Key points
- Epworth measures DAYTIME SLEEPINESS, the likelihood of dozing off in 8 everyday situations. It does not measure insomnia.
- Eight situations, each scored 0 to 3, total 0 to 24. From 11 upwards is regarded as excessive daytime sleepiness.
- ⭐ People with chronic insomnia usually score LOW on Epworth, not high. They are exhausted but cannot doze off, which is a sign of hyperarousal and one of the ways insomnia is distinguished from sleep apnoea.
- A high Epworth score in someone who snores loudly is the situation that should prompt thinking about sleep apnoea and a sleep study.
Fatigue and sleepiness are not the same thing
This is the most common confusion and it changes the direction of the diagnosis entirely. "Fatigue" is a lack of energy: you lie down and still cannot sleep. "Sleepiness" is a tendency to fall into sleep: a few minutes sitting still and you nod off. Epworth measures the second one.
People with chronic insomnia describe being exhausted all day, but when asked "if you lay down right now, would you sleep?" the answer is usually no. So they score low on most of Epworth's eight situations. This paradox is not patients reporting inaccurately. It is a physiological feature of insomnia: the arousal system is over-active day and night.
| Situation | Chronic insomnia | Sleep apnoea |
|---|---|---|
| Epworth score | Usually low (0 to 8) | Usually high (11 or more) |
| Able to sleep when lying down in the day | Usually not | Usually asleep straight away |
| Main complaint | Cannot sleep, worry about sleep | Snoring, breathing pauses, sleepiness |
| First-line approach | CBT-I | A sleep study, then positive airway pressure if indicated |
The score bands and what they mean
- 0 to 10: within the normal range.
- 11 to 14: excessive daytime sleepiness, mild to moderate.
- 15 to 24: excessive daytime sleepiness, severe. The cause needs finding, and you should not be driving long distances at this level.
About the copyright of this questionnaire
The Epworth Sleepiness Scale was developed by Murray W. Johns in 1991. Its licensing terms are stricter than most other scales: a licence is required for EVERY form of use, paid or otherwise, and reproduction without written consent is explicitly prohibited. This page therefore explains the scale and how to read it, without reprinting the questionnaire. The scale also has no published validated Vietnamese version.
Frequently asked questions
- My Epworth score is low. Does that mean my sleep is fine?
- That cannot be concluded. Epworth only says you rarely doze off during the day. People with severe insomnia routinely score low on it. To assess insomnia, use a screen based on the diagnostic criteria.
- I found a Vietnamese version of Epworth online. Can I use it?
- You can take it for your own reference, but bear two things in mind: the scale is copyrighted, and freely circulating translations are usually not validated, so the wording can shift the score. During a consultation the doctor uses the official version.
References
- A new method for measuring daytime sleepiness: the Epworth sleepiness scale - Sleep, 1991
- Epworth Sleepiness Scale - licensing terms for use - Epworth Sleepiness Scale (Murray W. Johns), 2026
- Clinical Practice Guideline for Diagnostic Testing for Adult Obstructive Sleep Apnea - American Academy of Sleep Medicine, 2017 · DOI 10.5664/jcsm.6506