Epworth Sleepiness Scale Calculator

The Epworth Sleepiness Scale (ESS) is a validated, self-administered questionnaire developed by Dr. Murray Johns at Epworth Hospital, Melbourne, and first published in 1991 in the journal Sleep. It measures chronic daytime sleepiness by asking respondents to rate their chance of dozing in 8 everyday situations on a 0 (never doze) to 3 (high chance of dozing) scale. Total scores range from 0 to 24. The ESS is widely used in sleep medicine clinics, primary care screening, and research studies worldwide.

Scores from 0 to 10 are considered within the normal range; most healthy adults without a sleep disorder score between 2 and 10. A score of 11 or above indicates some degree of excessive daytime sleepiness. The clinical thresholds are: 0–10 normal; 11–12 mild; 13–15 moderate; 16–24 severe excessive daytime sleepiness. Some guidelines use a cut-off of 11 for clinical follow-up; others use 10 or higher as the threshold for investigation.

The most common causes include: obstructive sleep apnea (OSA), where partial upper-airway blockages during sleep cause repeated micro-arousals; chronic insufficient sleep (behavioural sleep insufficiency); insomnia, where poor sleep quality leaves the person unrefreshed; narcolepsy and idiopathic hypersomnia (rare); restless leg syndrome and periodic limb movement disorder; circadian rhythm disorders; depression and anxiety; hypothyroidism; and sedating medications such as antihistamines, benzodiazepines, and opioids.

Yes. The ESS has been extensively validated across multiple cultures, age groups, and languages. It demonstrates good internal consistency (Cronbach's alpha 0.73–0.88 across studies), strong test-retest reliability over a four-week interval, and significant correlations with objective measures including the multiple sleep latency test (MSLT) and polysomnographic apnea-hypopnea index (AHI). It is included in major clinical practice guidelines for OSA screening by the American Academy of Sleep Medicine (AASM).

The Epworth Sleepiness Scale (ESS) measures excessive daytime sleepiness — the tendency to doze in passive situations. The Pittsburgh Sleep Quality Index (PSQI) measures sleep quality over the past month across seven components: subjective sleep quality, latency, duration, efficiency, disturbances, use of sleeping medication, and daytime dysfunction. The ESS is a 1-minute screen; the PSQI takes 5–10 minutes. They measure different constructs and are often used together: the ESS identifies who is sleepy during the day; the PSQI identifies who sleeps poorly at night.

An ESS score above 10 warrants a discussion with your doctor, particularly if the sleepiness affects your work, driving safety, or quality of life. Your doctor may ask about snoring, witnessed apneas, and morning headaches (which suggest OSA) and may order a home sleep apnea test or full polysomnography. Scores above 15 are particularly likely to reflect an underlying sleep disorder requiring treatment.

Yes. Obstructive sleep apnea (OSA) is the single most common cause of high ESS scores in adults. In OSA, repeated airway obstructions fragment sleep architecture and suppress deep restorative sleep, leaving patients profoundly sleepy during the day despite spending adequate time in bed. Studies show mean ESS scores of 12–16 in untreated moderate-to-severe OSA patients. Effective CPAP therapy typically reduces ESS scores by 4–8 points within weeks.

Yes. Chronic sleep deprivation (sleeping less than your biological need) reliably increases ESS scores. Even mild restriction — 1 to 2 hours less than needed per night — can elevate ESS scores by 3–5 points after several consecutive days. However, ESS was designed to measure pathological sleepiness, not lifestyle sleepiness. If your score normalises after a period of adequate sleep, the cause was behavioural sleep insufficiency rather than an underlying disorder.

Taking the ESS every 3–6 months provides useful longitudinal data, especially if you are undergoing treatment for a sleep disorder. Re-testing after starting CPAP therapy, changing sleep habits, or treating a medical condition shows whether the intervention is working. For healthy individuals without symptoms, a single periodic baseline screening is sufficient unless sleepiness develops or worsens.

The ESS is a useful screening tool for narcolepsy — people with narcolepsy type 1 typically score between 17 and 22. However, the ESS alone cannot diagnose narcolepsy, which requires the multiple sleep latency test (MSLT) showing a mean sleep onset latency of 8 minutes or less with two or more sleep-onset REM periods, plus CSF hypocretin-1 measurement (in type 1). The ESS can flag a patient for further investigation.

Yes. For children aged 2–12, modified pediatric ESS versions exist that replace adult situations with age-appropriate ones (e.g., 'while watching a video' instead of 'while watching TV'). The Pediatric Daytime Sleepiness Scale (PDSS) is also commonly used for school-age children. For teenagers (ages 13+), the standard adult ESS is generally considered applicable, though normative values are slightly different from the adult population.

Sleep disorders commonly associated with elevated ESS scores (above 10): obstructive sleep apnea (OSA) — most common, mean ESS 12–16 in moderate-severe cases; narcolepsy type 1 and 2 — typically ESS 17–22; idiopathic hypersomnia — ESS often 14–18; restless leg syndrome and periodic limb movements — mild elevation; circadian rhythm sleep-wake disorders (e.g., shift work disorder, delayed sleep-wake phase disorder) — variable but often elevated. Upper airway resistance syndrome (UARS) — similar to OSA but harder to detect.

Yes. Many medications cause or worsen daytime sleepiness and can raise ESS scores: antihistamines (diphenhydramine, chlorphenamine), benzodiazepines and Z-drugs (lorazepam, zolpidem), opioid analgesics, antiepileptics (gabapentin, pregabalin, carbamazepine), antidepressants with sedating profiles (mirtazapine, amitriptyline, doxepin), antipsychotics, muscle relaxants, and beta-blockers. If you recently started a new medication and notice increased sleepiness, report the elevated ESS score to your prescriber.