Narcolepsy is a sleep disorder marked by extreme drowsiness and bouts of sudden deep sleep at inopportune times. These “sleep attacks” can leave a person feeling exhausted, even after extended periods of sleep. Narcolepsy is a lifelong, chronic condition that affects more than 100,000 Americans.1
Narcolepsy is typically characterized by five main symptoms. These include excessive daytime sleepiness, sleep paralysis, disrupted nighttime sleep, hallucinations, and cataplexy.2
Excessive daytime sleepiness is the persistent state of tiredness that is not the result of sleep deprivation. This is a universal symptom of narcolepsy and is present in all patients with narcolepsy. Many sleep disorders, such as insomnia and sleep apnea, are centered on an inability to sleep or reach deep sleep. Narcolepsy is unique in that people with narcolepsy experience excessive daytime sleepiness as a recurring uncontrollable urge to fall asleep throughout the day. This can happen at any point during the day, even in the middle of a conversation or while doing an activity, such as driving. These episodes of sleep may last anywhere between a few seconds and a half hour, often reaching REM sleep much faster than individuals without narcolepsy.3,4
Another symptom of narcolepsy is sleep paralysis. Sleep paralysis usually occurs while falling asleep or waking up. During this period, which can last several minutes, the brain is fully awake and functioning while the body is still asleep and unable to move. This can coincide with feelings of being pushed down, fear, and a sense as though there is someone else in the room.5
Trouble sleeping or disrupted sleep is another common symptom of narcolepsy. People with narcolepsy often have little trouble falling asleep, but struggle to sleep through the night. They may wake up frequently, act out while sleeping, or have unusually vivid nightmares. Often people who suffer from narcolepsy find that their daytime sleepiness is in fact made worse by disjointed sleep at night.
Narcolepsy can also cause dream-like hallucinations. These can be either hypnagogic or hypnopompic, which means they occur either as the individual is falling asleep or as they are waking up, respectively.6 These hallucinations occur because people with narcolepsy go from waking to reaching levels of deep REM sleep unusually quickly. This means that they experience vivid hallucinations when they are half-awake, in between dreaming and waking.7
Finally, the most distinctive indicator of narcolepsy (besides excessive daytime sleepiness) is cataplexy. Cataplexy is the sudden loss of muscle control or muscle weakness. This usually manifests as a slack jaw, slurred speech, buckling knees, or full body collapse. These periods of loss of muscle control are generally triggered by experiencing an intense emotion such as joy, fear, anger, or excitement.8
However, not everyone with narcolepsy displays all five of these symptoms, which can make it hard to diagnose.
Narcolepsy symptoms can develop at any time, but most often begin to appear during childhood and adolescence. Signs of narcolepsy may appear slowly and level out with time.9 Because the signs of narcolepsy overlap with many other major sleep disorders and mental health conditions, narcolepsy often goes undiagnosed.
There are two distinct classifications of narcolepsy, Type 1 and Type 2. These are defined by the presence of specific, observable signs of narcolepsy. Narcolepsy Type 1 is classified as the combination of the presence of excessive daytime sleepiness, cataplexy, and/or low levels of the brain chemical hypocretin. Hypocretin is a neuropeptide that promotes wakefulness. People who have low levels of hypocretin often experience continued drowsiness and the inability to control REM sleep.10
Narcolepsy Type 2 involves excessive daytime sleepiness without the presence of cataplexy or low hypocretin levels. The origins of narcolepsy without cataplexy and/or low levels of hypocretin are still unknown.11
If you are experiencing any of the five core symptoms of narcolepsy, including excessive daytime sleepiness, it is important to seek professional medical help from a sleep specialist in order to get a diagnosis. There are several sleep tests that can quite accurately test for narcolepsy. These sleep studies can include a polysomnography and a multiple sleep latency test.12
Narcolepsy causes include injury, genetic family history, autoimmune disorders, and low levels of the brain hormone hypocretin. The onset of narcolepsy generally happens sometime between early childhood and adolescence, although it can manifest at any point.
No, narcolepsy is a life-long sleep disorder that does not intensify with age.
Untreated narcolepsy can make it difficult to function in the everyday world and can cause depression, anxiety, and social isolation. Narcolepsy treatment depends on the type and the acuteness of the symptoms.
Currently, there is no cure for narcolepsy. However, there are many medications, lifestyle changes, and sleep routines that minimize the impact of narcolepsy and allow people to lead a fully functional and fulfilling life.
© 2021 American Sleep Association.