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Excessive Daytime Sleepiness


If you have trouble waking up, feel tired throughout the entire day (not only after lunch), have trouble concentrating and performing your daily tasks, and struggle to stay awake, you are likely to be experiencing Excessive Daytime Sleepiness. This is not a sleep disorder, but rather a symptom.

EDS may suggest you haven’t had enough sleep lately, are going through a rough period, or indeed have a sleep disorder which is manifested by Excessive Daytime Sleepiness, among other symptoms.

According to the National Sleep Foundation, about 20% of adults have Excessive Daytime Sleepiness. This symptom extremely rarely occurs in children, whereas adolescents and adults (especially shift workers and older persons) are at a higher risk of experiencing it.

Having a strong need for sleeping is also known as hypersomnia. This term, however, doesn’t only refer to EDS, but it also means sleeping for a long time during day and night.

How do you know whether you have Excessive Daytime Sleepiness?

Excessive Sleepiness frequently goes unreported, as people usually don’t see it as a legitimate reason to consult a doctor. However, if you experience several of the listed issues, you should consider seeing your GP.

  • Fatigue is described as a general lack of physical and mental energy. Clinical fatigue contains mental and physical components:
    • general weakness
    • getting excessively tired shortly after beginning an activity
    • experiencing problems with mental stability, memory, and concentration
  • Need for frequent naps which don’t help with the condition.
  • Dozing off at inappropriate moments – while driving or during a conversation
  • Loss of appetite.
  • Poor performance at work or school.
  • Easy irritability.

Excessive Daytime Sleepiness is not strictly defined and it may be difficult to recognize it. If you decide to consult a doctor from a sleep center, they may give you one of the frequently used tests. For example, the Epworth Sleepiness Scale (ESS) – which is a subjective questionnaire, or Multiple Sleep Latency Test (MSLT), which is more objective as respondents are required to take naps after which their sleep latency is measured.

What causes Excessive Daytime Sleepiness?

There are a number of reasons that cause EDS – some of which can be easily fixed by following simple healthy sleep rules. On the other hand, EDS may be caused by some serious sleep disorders which require immediate professional attention. Here are some of the most frequent causes of Excessive Daytime Disorder, from Dr. Pagel’s article published in American Family Physician:

  • Primary hypersomnias of central origin (these disorders happen on their own, that is, they are not caused by another condition):
  • Narcolepsy. EDS may be a symptom of narcolepsy. This rare disorder (affecting between 0.02 and 0.18% of the population) can be dangerous. People with narcolepsy are extremely tired and even tend to fall asleep while performing their daily tasks. To fall asleep during driving is dangerous to their environment and to themselves. Narcolepsy causes early REM onset – instead of reaching it about 90 minutes into sleep, those who suffer from narcolepsy either fall directly into rapid eye movement stage or reach it within 10 minutes.
  • Idiopathic hypersomnia is diagnosed with those who very frequently – although not always – sleep for at least 11 hours per day. Even after such a long period of sleep, they do not feel refreshed. These people may have difficulty waking up to alarms, thinking and moving after being suddenly awakened – sleep inertia.

Secondary hypersomnias (they are caused by a different disorder, or are related to it) may come from:

  • Obstructive sleep apnea – OSA (also spelled as sleep apnoea) appears in 2% of the female and 4% of the male population. It is a sleep breathing disorder which happens after the airway is blocked and breathing stops. Sufferers from OSA wake up frequently during the night, although the following day they may not be aware of what happened.
  • Behavioral sleep deprivation. This refers to the lifestyle which may cause Excessive Daytime Disorder. It occurs in shift workers, adolescents, those who frequently go out for the night, and consumers of alcohol and caffeine (in excessive amounts).
  • Circadian rhythm and sleep-related disorders.
  • Drugs. Whether prescribed, unprescribed or drugs of abuse – they may interfere with the circadian rhythm or sleep stages. Some drugs may prevent a patient from reaching deep sleep or REM sleep, which can easily cause a person to become excessively sleepy during the day.
  • Depression. Depression is linked to chronic fatigue. However, some studies have even shown that those who were deprived of sleep managed to normalize levels of certain chemicals in the brain and quickly improve their condition.
  • Emotional shock, stress, anxiety. Any form of psychological distress may deprive you of the much-needed restorative deep sleep or REM sleep.
  • Medical conditions such as traumatic brain injury, encephalitis, cancer, stroke, inflammation, and neurodegenerative diseases (such as ALS, or amyotrophic lateral sclerosis, for example. ALS patients are likely to experience OSA).
  • Restless leg syndrome (RLS). Those who suffer from RLS have an urge to move their legs. Especially during the night, after a period of restfulness, they feel an unpleasant sensation or even pain in their legs. This need negatively impacts their nighttime sleep quality and quantity.
  • Insomnia. Although insomniacs may be given ideal sleep conditions, they would still stay awake, unable to fall asleep. Insomnia is almost always followed by fatigue.

All of the listed disorders have one thing in common – they impair sleep quality and quantity. This means either less time sleeping or less time getting all of the needed sleep stages.

For example, if you sleep 8 hours every night, but due to prescribed medications are unable to reach REM or deep sleep, your brain will only be able to have light sleep. This means no memory consolidation, cell restoration, serotonin and dopamine replenishment – virtually none of the benefits offered by REM and deep sleep.

Such a person is sleep deprived with all of the dangers sleep deprivation carries.

How is Excessive Daytime Sleepiness treated?

Depending on the primary reason for Excessive Daytime Sleepiness, sleep medicine offers various treatments.

If a teenager stays up late watching films, a technology curfew may be a solution. For sufferers of sleep apnea, nasal continuous positive airway pressure (CPAP) treatment helps restore sleep quality, whereas sodium oxybate is approved for treating EDS caused by narcolepsy. Those diagnosed with depression or anxiety may have to consult a professional and take additional care of their mental health.

Although some authors argue that the focus of treatment should solely be on the underlying cause, some believe that medications should be used if the cause treatment isn’t completely effective.

Additional Resources

  1. Ronald D Chervin, Approach to the patient with excessive daytime sleepiness. September 14, 2017. https://www.uptodate.com/contents/approach-to-the-patient-with-excessive-daytime-sleepiness Accessed December 7, 2018.
  2. How To Sleep Better – The Ultimate Guide to Catching More Z’s. Sleepline. November 14, 2018. https://www.sleepline.com/how-to-sleep-better/ Accessed December 7, 2018.
  3. Pagel, J.F, Excessive Daytime Sleepiness. American Family Physician. March 1, 2009. https://pdfs.semanticscholar.org/0fe3/00851b82c5feaf1f11766c91d5d487fd7d1b.pdf
  4. REM Sleep – How It Works and What The Benefits Are. Sleepline. December 8, 2018. https://www.sleepline.com/rem-sleep/ Accessed December 8, 2018.
  5. Circadian Rhythm and Sleep. Sleepline. November 14, 2018. https://www.sleepline.com/circadian-rhythm-and-sleep/  Accessed December 7, 2018.
  6. The Four Stages Of Sleep And Sleep Cycles. Sleepline. December 8, 2018. https://www.sleepline.com/stages/ Accessed December 8, 2018.
  7. How To Get More Deep Sleep. Sleepline. November 14, 2018. https://www.sleepline.com/how-to-get-more-deep-sleep/ Accessed December 7, 2018.
  8. Sleep Deprivation – How Losing Sleep Can Ruin Your Health. Sleepline. November 14, 2018. https://www.sleepline.com/sleep-deprivation/ Accessed December 7, 2018.
  9. Banerjee D, Vitiello M.V, Grunstein R.R, Pharmacotherapy for excessive daytime sleepiness. Sleep Medicine Reviews. October 2008.
    https://www.ncbi.nlm.nih.gov/pubmed/15336235 doi: 10.1016/j.smrv.2004.03.002
  10. Classification of Hypersomnias. Hypersomnia Foundation. https://www.hypersomniafoundation.org/classification-of-hypersomnias/ Accessed December 7, 2018.

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