Epworth Sleepiness Scale: What Your Score Means and When to Act

The Epworth Sleepiness Scale (ESS) is a short questionnaire that measures how sleepy you are during the day. You rate how likely you are to doze off in eight everyday situations, giving a total from 0 to 24. Scores of 0 to 10 are in the normal range, and 11 or more suggests excessive daytime sleepiness worth discussing with a doctor.

This guide covers who created the scale, what it does and does not measure, what each score band means, its limits, the common causes of daytime sleepiness, and when to see a GP or doctor.

What is the Epworth Sleepiness Scale?

The ESS is a self-completed questionnaire used by doctors, sleep clinics and researchers worldwide. It asks you to rate your usual chance of dozing off in eight common situations, from quiet, passive ones to more active ones. It takes two or three minutes.

The questionnaire itself is copyrighted, and the official Epworth Sleepiness Scale website (epworthsleepinessscale.com) states that a licence is needed to use the standard version, whether or not a fee is payable. For that reason we do not reproduce the questions here. If your doctor wants you to complete it, they will give you a copy.

Who created the Epworth Sleepiness Scale, and when?

Dr Murray Johns, a sleep physician, developed the scale in 1990 for patients at his own practice and named it after Epworth Hospital in Melbourne, Australia.

The scale was first described in a 1991 paper in the journal Sleep. In 180 adults, total scores separated 30 healthy controls from patients with obstructive sleep apnoea, narcolepsy and idiopathic hypersomnia.

In 1997 one sentence was added to the instructions, encouraging people to answer every question. That 1997 version is the standard one used today.

What does the ESS measure, and what does it not?

The ESS estimates what Johns calls your average sleep propensity: how readily you tend to fall asleep across the range of situations in your normal life, over recent weeks to months. A higher total means you doze off more easily during the day.

It does not measure:

• Sleep quality. It does not ask how long you slept, how often you woke or how rested you feel.
• How alert you feel right now. It is about your usual pattern.
• Fatigue. Feeling tired, weary or low on energy is not the same as actually dozing off.
• The cause. A high score tells you that you are sleepy, not why.

This is also why the ESS is different from a sleep score on a wearable, which summarises last night.

How is the Epworth Sleepiness Scale scored?

Each of the eight situations is rated on a four-point scale from 0 to 3, where a higher number means a higher chance of dozing. The eight ratings are added together to give a total from 0 to 24. That total is the number clinicians use.

If any question is left blank, the official guidance says the score is not valid, because a missing answer cannot be estimated.

What does my Epworth score mean?

The official ESS website gives the following general interpretation. The Sleep Foundation uses the same bands.

What is a normal Epworth score?

The 1991 paper first put the normal range at 2 to 10. Later data changed that. In a 1997 study of Australian workers, people with no sign of a sleep disorder scored between 0 and 10, with an average of 4.6. Scores above 10 were taken to mean excessive daytime sleepiness, and 10.9% of the workers were in that group. The official site now gives the normal range as 0 to 10.

What is the ESS used for?

In the UK, the National Institute for Health and Care Excellence (NICE) guideline on obstructive sleep apnoea tells clinicians to use the ESS in the first assessment of sleepiness when sleep apnoea is suspected, and to consider a second questionnaire, STOP-Bang, alongside it. NICE also lists the ESS as one of the things to review when checking whether treatment such as CPAP is working.

According to the official site, scores fall after effective treatment for sleep apnoea and narcolepsy, which makes the scale useful for tracking change over months.

What are the limits of the Epworth Sleepiness Scale?

The ESS is a useful first step, but its author and independent reviewers both point to real limits.

1. It is self-report. Answers depend on memory and honesty. The official site warns against relying on the ESS alone where the result could have legal consequences, such as decisions about a driving licence.
2. It is not a diagnosis. The official site says plainly that the ESS cannot tell which factor or sleep disorder is causing sleepiness, and is not a diagnostic tool by itself.
3. A normal score does not rule out sleep apnoea. NICE says the ESS should not be used alone to decide whether someone needs referral, because not everyone with sleep apnoea feels excessively sleepy.
4. It works better for groups than individuals. A 2014 systematic review of 35 studies found good internal consistency, but weaker than expected links with lab sleep tests and sleep apnoea measures. The authors recommended it for group comparisons rather than individual ones.
5. Culture and background affect scores. The official site notes that ethnicity affects ESS scores, and that more evidence is needed before assuming the same normal range applies to every population.
6. It is not built for short-term changes. It looks back over recent weeks to months, so it cannot show the effect of one bad night or one dose of a sedating medicine.

What causes excessive daytime sleepiness?

A high score is a symptom with many possible causes. The Sleep Foundation groups the main ones like this:

• Not enough sleep. Chronic sleep loss from long hours, irregular schedules or insomnia is one of the most common causes.
• Poor or broken sleep. Frequent waking, for example to use the toilet, breaks up the night. Our guide to sleep stages explains why unbroken cycles matter.
• Sleep disorders. These include obstructive sleep apnoea, restless legs syndrome, periodic limb movement disorder, narcolepsy, idiopathic hypersomnia and body clock (circadian rhythm) disorders.
• Other health conditions. Depression, anxiety, an underactive thyroid, chronic pain, obesity and several neurological conditions can all cause sleepiness.
• Medicines and substances. Some medicines list drowsiness as a side effect, and alcohol can cause it too.

If the cause is simply too little sleep, the fix starts with time in bed. Our article on how to get more deep sleep covers the habits with the best evidence.

When should you see a GP or doctor about daytime sleepiness?

You do not need a questionnaire score to book an appointment. Based on NHS guidance on sleep apnoea and on narcolepsy, plus the Sleep Foundation's advice, see a GP or doctor if:

• you always feel very tired or sleepy during the day, even after enough time in bed
• someone has noticed your breathing stopping and starting while you sleep, or gasping, snorting or choking noises
• you snore loudly and also feel sleepy in the day
• you fall asleep suddenly during the day, or have episodes of sudden muscle weakness, often triggered by laughing or strong emotion
• sleepiness is getting in the way of daily life or putting your safety at risk

The NHS says sleep apnoea can be serious if it is not diagnosed and treated. Its narcolepsy page suggests keeping a diary of your symptoms and sleep for a few weeks before the appointment. If you have completed an ESS, take the score with you. This is NHS guidance from the UK. If you live elsewhere, your own doctor or health service may follow a different route.

Daytime sleepiness and driving (UK guidance)

Sleepiness and driving do not mix. The UK government's guidance on excessive sleepiness and driving says you must tell the DVLA if you have confirmed moderate or severe obstructive sleep apnoea with excessive sleepiness, narcolepsy or cataplexy, or any other sleep condition that has caused excessive sleepiness for at least 3 months. You must not drive until you are free from excessive sleepiness, and you can be fined up to £1,000 for not telling the DVLA about a medical condition that affects your driving. If you are unsure whether your sleepiness affects your driving, ask your doctor.

These are UK rules: elsewhere, follow your local licensing authority. Wherever you are, if you start nodding off at the wheel, stop somewhere safe.

Can a smart ring tell you how sleepy you are?

No. A wearable can estimate how long you slept, your sleep stages and your overnight heart data, but it does not measure daytime sleepiness, and it cannot tell you whether you have a sleep disorder. The ESS and a ring answer different questions: one asks how sleepy you are in daily life, the other records what happened overnight.

Where they meet is in spotting patterns. If your daytime sleepiness lines up with short nights or late bedtimes, that is worth telling your doctor.

Frequently asked questions

What is a normal Epworth Sleepiness Scale score?

The official ESS website gives the normal reference range as 0 to 10. Scores of 0 to 5 count as lower normal daytime sleepiness and 6 to 10 as higher normal. In a study of Australian workers with no sign of a sleep disorder, the average score was 4.6. Scores of 11 or more suggest excessive daytime sleepiness.

Is an Epworth score of 10 bad?

No. A score of 10 sits at the top of the higher normal band, which runs from 6 to 10. It is not considered excessive daytime sleepiness. If you still feel sleepy enough to worry you, or you have symptoms such as loud snoring or pauses in breathing at night, speak to a GP or doctor anyway, because a normal score does not rule out a sleep disorder.

What does an Epworth score of 16 or more mean?

On the official interpretation, 16 to 24 means severe excessive daytime sleepiness. It does not tell you the cause, which could be lack of sleep, a sleep disorder such as sleep apnoea or narcolepsy, a medical condition or a medicine. A score this high is a clear reason to see a doctor soon, and to avoid driving if you feel sleepy.

Can the Epworth Sleepiness Scale diagnose sleep apnoea?

No. The ESS measures daytime sleepiness, not breathing during sleep. Many people with sleep apnoea are sleepy, but not all are, which is why NICE advises clinicians not to use the ESS alone to decide on referral. Diagnosing sleep apnoea needs a proper sleep assessment arranged by a doctor or sleep service.

Where can I find the official Epworth Sleepiness Scale questionnaire?

The questionnaire is copyrighted by its author, Dr Murray Johns, and a licence is needed to use the standard version. The official Epworth Sleepiness Scale website explains how it is used and licensed. If your doctor or sleep service wants you to complete it, they will provide a copy and interpret the result with you.

This article is for general information and is not medical advice. PulseRing Pro is a wellness device, not a medical device, and does not diagnose or treat any condition. If you are worried about your health, speak to your GP or a qualified clinician.