Advancements in the understanding of narcolepsy are happening. Register for updates »

Advancements in the understanding of narcolepsy are happening. Register for updates »

Evaluating for Ongoing Excessive Daytime Sleepiness in Narcolepsy

Hear how people may describe their excessive daytime sleepiness and gain insights to help enhance your clinical interview skills.

EDS video thumbnail

What Does Excessive Daytime Sleepiness (EDS) With Narcolepsy Feel Like?

Emily, Scott, Sharon, & Sean

Four people living with narcolepsy share their experience of what excessive daytime sleepiness (EDS) feels like for them.

Excessive daytime sleepiness in narcolepsy is more than just falling asleep.1,2

Excessive daytime sleepiness can also cause changes in wakefulness that may be difficult to recognize.2,3 People with excessive daytime sleepiness may use vague terms to describe their sleepiness, such as being “tired all the time,” “fatigue,” a “lack of energy,” or that they have “brain fog.” They may not recognize the extent of their sleepiness and may even deny being sleepy.2 However, even less obvious manifestations of excessive daytime sleepiness can have a substantial impact.3,4 The perspective of friends and family members is important when talking to your patients about their sleepiness.2

Listen carefully, and evaluate for:

  • Checkmark iconCharacteristics2,5
    • How often do you experience excessive daytime sleepiness?
    • Since it started, has there been any freedom from excessive daytime sleepiness?
  • Checkmark iconMore obvious excessive daytime sleepiness manifestations1
    • How often do you need to take naps during the day?
    • Do you ever fall asleep without warning?
    • How long do planned or unplanned naps last?
  • Checkmark iconLess obvious excessive daytime sleepiness manifestations1,2,4
    • How would you describe what sleepiness feels like to you?
    • Do you experience fatigue?
    • Have you had any difficulties with your mood, like irritability?
    • Do you ever do things or have conversations with people and not remember them happening?
  • Checkmark iconPropensity for sleepiness or dozing in different situations1,2,6
    • Do you tend to experience excessive daytime sleepiness when you are sitting still/inactive?
    • Do you ever experience excessive daytime sleepiness in more active situations, like when you are talking or eating?
  • Checkmark iconImpact of excessive daytime sleepiness1,2,7,8
    • Are there activities you avoid because of your EDS?
    • How has excessive daytime sleepiness affected your daily life?
    • What is the impact of excessive daytime sleepiness on your quality of life?

Sharon, living with narcolepsy

It was as if my brain was encapsulated by a thick fog.

Cataplexy icon

Manifestations of cataplexy are not always obvious.

Know the signs »
Other narcolepsy symptoms icon
Other Narcolepsy Symptoms

Learn more about recognizing other symptoms of narcolepsy.

Understand »

Excessive daytime sleepiness is generally the most disabling symptom of narcolepsy, although some manifestations may be difficult to recognize.1,2

Excessive daytime sleepiness icon

Excessive daytime sleepiness can cause obvious changes in wakefulness.1

The pressure for sleep may be so great that people living with narcolepsy experience brief lapses into sleep (microsleep episodes) and unplanned naps.1,3,4 They may also perform tasks such as writing, cooking, or having a conversation with no awareness or memory (automatic behavior).1,4,9

In patients complaining of excessive daytime sleepiness, the frequency of sleep-onset REM periods (SOREMPs) on Multiple Sleep Latency Test (MSLT) may help indicate clinical symptom severity.10

A study in patients with narcolepsy has shown that excessive daytime sleepiness severity is correlated with the degree of REM sleep dysregulation.10

Bar graph showing association between frequent SOREMPs on MSLT and shorter mean sleep latencies

In a study conducted between March 2004 and August 2009, the relationship between SOREMP frequency on MSLT and narcolepsy symptom severity was examined in 126 patients with narcolepsy. Narcolepsy symptom severity was assessed using the Epworth Sleepiness Scale (ESS), the Stanford Center for Narcolepsy Sleep Inventory, and various sleep parameters, including mean sleep latency.10

Other manifestations of excessive daytime sleepiness icon

Other manifestations of excessive daytime sleepiness may not be obvious.2,4

Even when seemingly awake, people living with narcolepsy rarely feel completely alert.1,4,11 They often struggle with poor memory, decision-making, or following a conversation.2,4

While people living with narcolepsy do not experience broad impairments in cognition, studies have shown that specific aspects of attention are particularly affected in people living with narcolepsy,12-14 including:

  • Cognitive processing across an extended period of time
  • Increased information processing demands (e.g., ability to focus or to divide attentional resources)

Sustaining attention, concentrating, remaining awake during conversations or meetings, and reading can all become a struggle for patients with narcolepsy.2,4 Impairments sustaining attention are thought to be a direct result of compensatory strategies to avoid falling asleep.13

A study in patients with narcolepsy has shown that executive control of attention is correlated with objective sleepiness.15

  • Patients with altered executive control of attention had shorter sleep latencies and a higher frequency of SOREMPs on MSLT15
  1. American Academy of Sleep Medicine. International Classification of Sleep Disorders. 3rd ed. Text Revision. American Academy of Sleep Medicine; 2023.
  2. Ahmed IM, Thorpy MJ. Clinical evaluation of the patient with excessive sleepiness. In: Thorpy MJ, Billiard M, eds. Sleepiness: Causes, Consequences and Treatment. Cambridge, UK: Cambridge University Press; 2011:36-47.
  3. Overeem S, Reading P, Bassetti C. Narcolepsy. Sleep Med Clin. 2012;7:263-281.
  4. Thorpy M, Morse AM. Reducing the clinical and socioeconomic burden of narcolepsy by earlier diagnosis and effective treatment. Sleep Med Clin. 2017;12(1):61-71.
  5. Thorpy MJ, Dauvilliers Y. Clinical and practical considerations in the pharmacologic management of narcolepsy. Sleep Med. 2015;16(1):9-18.
  6. Johns M, Hocking B. Daytime sleepiness and sleep habits of Australian workers. Sleep. 1997;20(10):844-849.
  7. Daniels E, King MA, Smith IE, Shneerson JM. Health-related quality of life in narcolepsy. J Sleep Res. 2001;10(1):75-81. doi:10.1046/j.1365-2869.2001.00234.x
  8. Center for Drug Evaluation and Research (CDER). The Voice of the Patient: A Series of Reports From the US Food and Drug Administration's Patient-Focused Drug Development Initiative - Narcolepsy. US Food and Drug Administration; 2014. Accessed September 8, 2023.
  9. Ahmed I, Thorpy M. Clinical features, diagnosis and treatment of narcolepsy. Chest Med. 2010;31(2):371-381.
  10. Jeong JH, Jeong-Yu K, Yoo BE, et al. The correlation between clinical variables and sleep onset rapid eye movement period frequencies in narcoleptic patients. Sleep Med Res. 2010;1:15-19.
  11. Nishino S. Clinical and neurobiological aspects of narcolepsy. Sleep Med. 2007;8(4):373-399.
  12. Bellebaum C, Daum I. Memory and cognition in narcolepsy. In: Goswami M, Thorpy MJ, Pandi-Perumal SR, eds. Narcolepsy. Springer; 2016:233-243.
  13. Naumann A, Bellebaum C, Daum I. Cognitive deficits in narcolepsy. J Sleep Res. 2006;15(3):329-338.
  14. Rieger M, Mayer G, Gauggel S. Attention deficits in patients with narcolepsy. Sleep. 2003;26(1):36-43.
  15. Bayard S, Langenier MC, De Cock VC, Scholz S, Dauvilliers Y. Executive control of attention in narcolepsy. PLoS One. 2012;7(4):e33525.

Performance of routine tasks without awareness.

Sudden and brief loss of muscle tone, often triggered by strong emotions or certain situations. Narcolepsy with cataplexy is known as narcolepsy type 1.

Complete collapse to the ground; nearly all skeletal muscles are involved.

Only certain muscle groups are involved.

Biological clock mechanism that regulates the 24-hour cycle in the physiological processes of living beings. It is controlled in part by the SCN in the hypothalamus and is affected by the daily light-dark cycle.

Frequent awakenings and inappropriate transitions between states of sleep and wakefulness during nighttime sleep.

The inability to stay awake and alert during the day.

A neurotransmitter in the brain that supports wakefulness.

Vivid, realistic, and sometimes frightening dream-like events that occur when falling asleep.

Also known as orexin. A neuropeptide that supports wakefulness and helps suppress non-REM sleep and REM sleep.

Primary brain region for regulating the timing of sleep-wake states.

Unintentionally falling asleep due to excessive daytime sleepiness. Also known as “sleep attacks.”

Brief, unintentional lapses into sleep or loss of awareness.

A validated objective measure of the tendency to fall asleep in quiet situations.

People living with narcolepsy type 1 have low levels of hypocretin.

Narcolepsy without cataplexy; the cause of narcolepsy type 2 is unknown.

A state of sleep characterized by slower-frequency, more synchronized neuronal activity and decreased muscle tone. Deep stages help to restore the body.

A multiparameter test that monitors physiologic signals during sleep; used as a diagnostic tool in sleep medicine.

A state of sleep characterized by fast-frequency, desynchronized activity on EEG, vivid dreams, and loss of muscle tone. Normally occurs 60-90 minutes after sleep onset. Also known as “paradoxical sleep.”

Brief loss of control of voluntary muscles with retained awareness at sleep-wake transitions.

An abnormal sleep phenomenon characterized by REM sleep occurrence within 15 minutes of sleep onset; may occur during nighttime sleep or daytime napping.

A group of neurons located in the hypothalamus that are essential for promoting non-REM sleep. These neurons project to all wake-promoting regions to inhibit wakefulness and promote non-REM sleep during the night.