1. Causes of Fatigue Slideshow Pictures
2. Take the Sleep Quiz
3. Foods That Help or Harm Your Sleep Slideshow Pictures

Medical Author:

John P. Cunha, DO, FACOEP

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

View Full Profile

Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

View Full Profile

In this Article

• What is narcolepsy?
• How common is narcolepsy?
• What causes narcolepsy?
• What are the symptoms of narcolepsy?
• Excessive daytime sleepiness (EDS)
• Cataplexy
• Hypnagogic hallucinations
• Sleep paralysis
• Additional symptoms
• How is narcolepsy diagnosed?
• How is narcolepsy treated?
• Medications
• Non-drug treatments
• What is the outcome (prognosis) for patients with narcolepsy?
• What's in the future for narcolepsy?
• Narcolepsy At A Glance
• For more information
• Patient Comments: Narcolepsy - Treatments
• Patient Comments: Narcolepsy - Excessive Daytime Sleepiness
• Patient Comments: Narcolepsy - Experience
• Find a local Sleep Specialist in your town
• Narcolepsy Index

Hypnagogic hallucinations may be present in up to 50% of patients with narcolepsy. Hypnagogic hallucinations are dream-like experiences that occur during the transition from wakefulness to sleep, whereas hypnopompic hallucinations occur during the transition from sleep to wakefulness. These hallucinations may involve hearing, vision, touch, balance, or movement. They often incorporate images of the patient's environment into the dream-like images. The hallucinations are frequently vivid, bizarre, frightening, and disturbing for the patients. As a result, the patients may become fearful that they have or will develop a mental illness.

Sleep paralysis may be present in up to 50% of patients with narcolepsy. Sleep paralysis is a temporary inability to move or talk that occurs during sleep-to-wake or wake-to-sleep transitions. Episodes of sleep paralysis may last seconds to minutes. They can occur at the same time as hypnagogic (or hypnopompic) hallucinations. During sleep paralysis, breathing is maintained, although some patients may experience a frightening sensation of not being able to breathe.

Cataplexy, hypnagogic hallucinations, and sleep paralysis in patients with narcolepsy are referred to as REM related abnormalities because they are caused by REM sleep intrusions into wakefulness. (See the discussion of REM sleep in the section on sleep laboratory tests below.)

Disturbed nocturnal sleep with frequent awakenings and increased body movements may develop after the onset of the primary symptoms of narcolepsy. This additional symptom, along with excessive daytime sleepiness and the REM related abnormalities (cataplexy, hypnagogic hallucinations, and sleep paralysis), from the so-called "narcolepsy pentad" (a set of five symptoms).

Automatic behavior may occur in 60% to 80% of patients with narcolepsy. Automatic behavior is when patients carry out certain actions without conscious awareness, often with the unusual use of words (irrelevant words, lapses in speech). This behavior occurs while the patient is fluctuating between sleep and wakefulness.

Other complaints associated with narcolepsy may include eye disturbances due to sleepiness, such as blurred vision, double vision, and droopy eyelids.