Excessive Daytime Sleepiness (EDS) Causes, Symptoms, Treatment

We all sometimes feel sleepy during the day especially in the late afternoon as we wind up a tiring day at work. Even intense boredom can cause sleepiness as does long hours of studying. These episodes of daytime sleepiness are not common and not abnormal. It happens every now and then and is usually a result of the exertion that precedes it. However, for some people this feeling of sleepiness throughout the day never stops even after a relatively good night’s sleep. It can be a sign of a medical problem.

What is Excessive Daytime Sleepiness?

Excessive daytime sleepiness is a condition where a person feels sudden and uncontrollable urge sleep and may sometimes even fall asleep despite trying to stay awake. It can affect various aspects of a person’s life especially if it is persistent and long-standing. It is among the more common sleep disorders and affects up to 20% of the American population. Although the exact cause is not always clear it is mainly related to inadequate sleep at night. Even a short nap can help a person feel refreshed for a period of time thereafter.

Excessive Daytime Sleepiness vs Narcolepsy

Excessive daytime sleepiness should not be confused with narcoplepsy where a person cannot resist the sudden urge to sleep and may fall asleep anywhere and at anytime. All narcolepsy patients have excessive daytime sleepiness but not vice versa. Narcolepsy is a chronic condition for which there is no known cure as yet. Unlike with excessive daytime sleepiness, a good night’s sleep or even a short nap does not ease or resolve the sleepiness in narcolepsy.

Causes of Excessive Daytime Sleepiness

Sometimes the cause of excessive daytime sleepiness cannot be identified and it is considered as a primary hypersomnia. However, the cause is often due to one or more of the factors below and is therefore considered a secondary hypersomnia. The term hypersomnia simply means excessive sleepiness. It is considered secondary when it arises as a consequence of some other condition such as:

  • Insufficient sleep / sleep deprivation as is seen in shift workers and students staying up for later hours.
  • Obstructive sleep apnea which causes repeated waking due to cessation of breathing or poor quality sleep.
  • Sleep-related movement disorders like restless leg syndrome.
  • Circadian rhythm sleep disorders where the body’s internal clock is disrupted thereby affecting sleep and waking hours.
  • Medication, including certain over-the-counter (OTC) and prescription drugs.
  • Illicit substances like cocaine.
  • Mental health conditions like depression.
  • Trauma such as traumatic brain injury.
  • Diseases including encephalitis, cancer, stroke and a host of inflammatory and neurological conditions.
  • Breathing disorders and pain for any reason can also affect sleep at night.
  • Gastroesophageal reflux disease (GERD) which may be silent (asymptomatic).

Various studies have pointed towards sleep deprivation as a major factor in the prevalence of excessive daytime sleepiness these days. The lack of sleep may be intentional rather than due to any pathological (disease) factors or substance misuse. Shift work, occupational stresses, late night studying and social activities may prevent a person from sleeping at night and staying awake. This is further complicated with shifts that require people to then work in the day after working a few hours at night.

Collectively, it disturbs the circadian rhythm (internal clock) and affects a range of neurobiological functions. This can arise within a few days of insufficient sleep and may last a significant period of time until measures are taken to restore normal sleep patterns. However, it is important to note that sleep deprivation may not always be intentional. With psychological stress many people are unable to fall asleep due to concerns about life events and commitments despite wanting to sleep.

Signs and Symptoms

Apart from sleepiness which is an obvious symptom, there may be additional signs and symptoms:

  • Fatigue
  • Poor concentration
  • Impaired memory
  • Mood swings
  • Difficulty with decision-making
  • Slow reflexes
  • Poor coordination
  • Hallucinations (auditory and visual)

There are many other symptoms that can arise due to the sleepiness during daytime hours. It can affect academic, work and personal life in a host of different ways. At times these symptoms are mistaken for mental health conditions, learning disabilities and intoxication. The difficulty with coping can lead some people to use substances like stimulants to stay awake during the day and sedatives to sleep at night. This may not always be prescription medication and alcohol or illicit substances may be abused as a result.

Treatment of Excessive Daytime Sleepiness

The treatment of ESD largely lies on identifying the underlying condition that may be causing ESD and treating or managing it effectively. Therefore the treatment of excessive daytime sleepiness can vary significantly. Stimulants for daytime use and sedatives at night should not be the first choice of treatment for secondary ESD.  This may include:

  • Positive pressure ventilation devices like CPAP machines for obstructive sleep apnea.
  • Analgesics for pain although it should not be used solely¬† for its sedative properties.
  • Antidepressants for depression which may have added benefits for hypersomnias even without depression.
  • Antacids and acid-suppressing drugs for the treatment and management of acid reflux.

Once the underlying condition is treated or if the cause cannot be conclusively identified then the following medication may be used in the treatment of excessive daytime sleepiness.

  • Modafinil which is a drug that helps with staying awake. It is often preferred due to the lower abuse profile as compared to amphetamines.
  • Dextroamphetamine which is a potent central nervous system (CNS) stimulant.
  • Methylphenidate is a stimulant that is widely used for the treatment of attention deficit hyperactivity disorder (ADHD).
  • Pemoline is another stimulant that was previously used for ADD but is no longer available in the United States.

Proper sleep patterns can help overcome most cases of excessive daytime sleepiness and short naps may also be helpful provided that it does not affect nighttime sleep. People suffering with excessive daytime sleepiness should be educated about sleep hygiene, the practice of measures which helps a person fall asleep and stay asleep. These simple but effective tips for falling asleep should be adhered to strictly on an ongoing basis even if a person is using medication.


  1. www.aafp.org/afp/2009/0301/p391.html
  2. www.medicinenet.com/script/main/art.asp?articlekey=10472

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