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What are the early signs of narcolepsy?

Medically reviewed by Carmen Pope, BPharm. Last updated on Dec 9, 2021.

Official answer


One of the earliest signs of narcolepsy is suddenly falling asleep during the daytime, even if you have had a full night’s sleep. This excessive sleepiness is like a “sleep attack” or an overwhelming sense of sleepiness that comes on quickly, and narcolepsy should be considered if a child or teen habitually falls asleep in class, or an adult finds themselves constantly dozing off at work, despite having had a full night's sleep. In between these sleep attacks, people with narcolepsy have normal levels of alertness, particularly if they are doing something that keeps their attention. Narcolepsy most commonly starts in young adults, aged 15 to 25, although it can occur at any age.

Sleep attacks are a hallmark of narcolepsy and are experienced by 100% of people with the condition. The following are other symptoms of narcolepsy, but these are only experienced by 10 to 25 percent of people:

  • Cataplexy – This symptom may appear weeks or years after the onset of excessive daytime sleepiness, although in about 10% of people this is the first symptom to appear. Cataplexy is sudden muscle weakness that may cause your eyelids or face to droop, your head to drop, or your knees to give way. It is usually triggered by strong emotions like embarrassment, laughter, surprise, or anger. But even during the most severe attacks, people remain fully conscious. Most episodes last a few minutes at the most and get better by themselves.
  • Sleep paralysis – This is a short-lived inability to move or speak that only lasts a few seconds or minutes that resembles cataplexy but only occurs while falling asleep or waking up. As with cataplexy, people remain fully conscious.
  • Hallucinations – These are very vivid and sometimes frightening hallucinations that usually occur when people are falling asleep or waking up. They are usually visual but any of the other senses can be involved.

Disturbed nighttime sleep or fragmented sleep affects up to 50% of people with narcolepsy. Sleep may be disrupted by vivid dreaming, insomnia, sleep apnea, acting out while dreaming, or periodic leg movements.

Carrying on with automatic behaviors, such as typing, drawing, eating, or even driving while experiencing a temporary sleep episode can also occur in some individuals with narcolepsy. They cannot recall their actions, and their performance is almost always impaired, for example, their handwriting may degenerate into an illegible scrawl or they store items in bizarre locations and then forget where they placed them. If the episode occurs while driving, the individual may get lost or have an accident. People usually awaken from these episodes feeling refreshed and find that their drowsiness and fatigue have temporarily subsided.

  • Identifying Narcolepsy Symptoms Is Important Narcolepsy Link. 2021.
  • Narcolepsy Fact Sheet National Institute of Neurological Disorders and Stroke 2021.
  • The Early Signs of Narcolepsy. April 21, 2020. Encroe Research Group.

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