Performance of routine tasks without awareness or memory.
Difficulty focusing or concentrating.
Brief loss of muscle tone with retained awareness, often triggered by strong emotions.
Frequent shifts between different states of sleep and wakefulness at night.
The inability to stay awake and alert during the day; a constant need for sleep or unintentionally falling asleep.
A chemical in the brain that helps maintain wakefulness.
Vivid, realistic, and frightening dream-like events that occur when falling asleep.
Dream-like events that occur when falling asleep. Called hypnopompic hallucinations if they occur when waking up.
A chemical in the brain that helps maintain wakefulness and prevent non-REM sleep and REM sleep from occurring at the wrong time.
Unintentionally falling asleep due to excessive daytime sleepiness; “sleep attacks.”
Restorative sleep state with decreased muscle tone.
Occurs at night and includes vivid dreams; muscles are not active to prevent people from acting out dreams.
Daytime and evening habits to improve sleep.
Brief total loss of voluntary muscle control when falling asleep or while waking up.
People with type 1 narcolepsy can be diagnosed by their cataplexy or low levels of hypocretin.
The cause of type 2 narcolepsy is unknown.