Narcolepsy is a nervous system problem that causes extreme sleepiness and attacks of daytime sleep.
Daytime sleep disorder; Cataplexy
Experts aren't sure of the exact cause of narcolepsy. It may have more than one cause.
Many people with narcolepsy have low levels of hypocretin (also known as orexin). This is a chemical made in the brain that helps you stay awake. In some people with narcolepsy, there are fewer of the cells that make this chemical. This may be due to an autoimmune reaction. An auto immune reaction is when the body's immune system mistakenly attacks healthy tissue.
Narcolepsy can run in families. Researchers have found certain genes linked to narcolepsy.
Narcolepsy symptoms usually first occur during ages 15 - 30. Below are the most common symptoms.
Extreme daytime sleepiness
You may feel a strong urge to sleep, often followed by a period of sleep. You can't control when you fall asleep. This is called a sleep attack.
These periods can last from a few seconds to a few minutes.
They may happen after eating, while talking to someone, or during other situations.
Most often, you wake up feeling refreshed.
Attacks can occur while you are driving or doing other activities where falling asleep can be dangerous.
During these attacks, you can't control your muscles and can't move. Strong emotions, such as laughter or anger, can trigger cataplexy.
Attacks often last from 30 seconds to 2 minutes. You remain aware during the attack.
During the attack, your head falls forward, your jaw will drop, and your knees may buckle.
In severe cases, you may fall and stay paralyzed for as long as several minutes.
You see or hear things that aren't there, either as you fall asleep or when you wake up.
Allen J. Blaivas, DO, Clinical Assistant Professor of Medicine, Rutgers New Jersey Medical School, Attending Physician in the Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Veteran Affairs, VA New Jersey Health Care System, East Orange, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.