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Narcolepsy is a relatively rare sleep disorder characterized by excessive daytime sleepiness and a tendency to sleep at inappropriate times. Narcolepsy affects both men and women. The symptoms usually begin during the teen or young adult years. However, it can develop in children, although rarely before the age five, and also later in life.

Causes of Narcolepsy

Most people who suffer from Narcolepsy have low levels of hypocretin, according to the National Institutes of Health. Hypocretin is a chemical in the brain that helps promote wakefulness. Although the factors that cause low hypocretin levels aren’t well understood, researchers think that certain factors may work together to cause a lack of hypocretin. They include:

  • Heredity. About 10 percent of people who have Narcolepsy have a relative who has the same symptoms.
  • Infections.
  • Brain injuries caused by brain tumors, strokes, trauma or other conditions.
  • Autoimmune disorders, in which the body's immune system mistakenly attacks its cells and tissues.
  • Low levels of histamine, a substance in the blood that promotes wakefulness.

Signs and Symptoms of Narcolepsy

  • Trouble falling and staying asleep at night.
  • Extreme daytime sleepiness and a tendency to sleep at inappropriate times. Not feeling mentally alert, memory or focus problems, lack of energy, exhaustion or depression.
  • Cataplexy, or muscle weakness in part or all of the body, often triggered by strong emotions such as anger, laughter or surprise. Cataplexy can be mild, such as a brief feeling of weakness in the knees, or it can cause a total loss of muscle control, resulting in a fall. It can last a few seconds or minutes, usually while you’re awake.
  • Sleep paralysis, which is a brief loss of muscle strength and an inability to move or speak, usually for no more than a few minutes, while waking up or falling asleep.
  • Hallucinations, or vivid dreams, while falling asleep, waking or dozing. Sufferers report not only being able to see these visions, but being able to hear, smell and taste them.

People with Narcolepsy may experience one or more of these symptoms, ranging from mild to severe, but less than one in three people report having all of the symptoms.


Sufferers may find it difficult to function at school, work, home, and in social situations because of extreme sleepiness. If not recognized and appropriately managed, Narcolepsy can drastically and negatively affect the quality of life.

What to Do

If you experience any of the symptoms of Narcolepsy and especially if they are impacting your ability to drive, perform you daily activities or interfering with your social activities and personal relationships, see your physician or one of our board certified sleep specialists. You will be diagnosed based on your symptoms, your medical and family histories, and a physical examination and testing. If it is suspected that you have narcolepsy, you may be asked to undergo sleep studies. Two studies, the polysomnogram (PSG) and the multiple sleep latency test (MSLT), are often performed to confirm the diagnosis of narcolepsy and to determine its severity.

A PSG is taken overnight and measures 16 body signals including: breathing, oxygen levels, heart rate, blood pressure, brain activity, eye movements and muscle movements, and can help determine whether you fall asleep quickly, how soon after falling asleep you enter rapid eye movement (REM) sleep and how often you wake during the night.The MSLT, a daytime sleep study often done the morning after the PSG, measures how sleepy you are. You will be asked to nap for 20 minutes every two hours throughout the day, and you may nap as many as four or five times. A technician monitors your brain activity and records how quickly it takes you to fall asleep during the day, after a full night’s sleep, and how long it takes to reach the various stages of sleep. Although narcolepsy cannot yet be cured, many of its symptoms may be relieved through medicines, lifestyle changes and other therapies.