Narcolepsy is a lifelong sleep disorder that makes you feel overwhelmingly tired, and in severe cases, have sudden uncontrollable sleep attacks. Narcolepsy can impact nearly every aspect of your life. It is dangerous because you can have excessive sleepiness or a sleep attack at any time of the day, in the middle of any activity including eating, walking or driving. Operating a vehicle with untreated narcolepsy can be very dangerous and some states even have laws against it.
Many people with narcolepsy do not know they have the sleep disorder. About one in 2,000 people have some form of narcolepsy. Narcolepsy may run in some families, but most cases are not genetic. The disorder is extremely rare in children. The cause of narcolepsy is still unknown, but recent research suggests that many people with narcolepsy with cataplexy have low levels of the neurotransmitter hypocretin, a chemical that regulates arousal, wakefulness and appetite.
There are two types of narcolepsy:
- Narcolepsy with cataplexy – This type of narcolepsy involves a combination of excessive daytime sleepiness and cataplexy. Cataplexy is when you have attacks that cause a sudden loss of muscle tone while you are awake. It may lead to slurred speech and buckling knees, or in more severe cases complete paralysis. These events are usually triggered by strong emotions such as joy, surprise, laughter or anger.
- Narcolepsy without cataplexy – This type of narcolepsy occurs when you have continuous excessive sleepiness but no cataplexy. You may take a nap for a couple of hours and wake up feeling refreshed. But after a short time, you feel tired again.
When you add up the hours of total sleep time, people with narcolepsy don’t necessarily sleep any more than people who don’t have the sleep disorder. This is especially true when you consider that many people with narcolepsy often have difficulty sleeping through the night because of unwanted awakenings.
Some people assume that because they are consistently tired during the day, that they may have narcolepsy. Other sleep disorders that cause daytime sleepiness are often mistaken for narcolepsy. These include sleep apnea, circadian rhythm sleep disorders and restless legs syndrome. Medical conditions, mental health disorders and use of certain medications or substances can also cause symptoms similar to narcolepsy.
Symptoms of narcolepsy usually begin between the ages of 15 to 25, but it is possible start experiencing symptoms at a much younger or older age. The symptoms usually worsen after the first few years. You may experience the following:
Excessive daytime sleepiness
The primary symptom of narcolepsy is excessive daytime sleepiness. You may feel tired during the day even though you had a full night’s sleep. This sleepiness is difficult to prevent and may vary over the course of the day. After a brief nap, you may feel alert, but the sleepiness will return after an hour or two.
Some patients with narcolepsy have vivid hallucinations at sleep onset. These hypnagogic hallucinations are usually visions that someone or something is present in your bedroom. It can feel very real, and trigger feelings of fear or dread. Other common visions may include being caught in a fire or flying through the air. These experiences are mainly visual, though they may also involve your senses of sound, touch, taste and smell.
You might lose the ability to move and feel paralyzed when you are falling asleep or waking up. This usually lasts a few seconds or minutes. This can be frightening, but it is not associated with an inability to breathe. Sleep paralysis can sometimes be paired with hallucinations, which are especially upsetting.
Disturbed nighttime sleep
About half of people with narcolepsy have problems sleeping through the night. You may wake up frequently and have difficulty falling back to sleep.
You may have trouble remembering things that people tell you because you were not fully awake at the time. Memory lapses also happen when sleepiness sets in as you are doing activities that do not require much thought.
Sudden loss in muscle tone (cataplexy)
This only occurs if you have narcolepsy with cataplexy. Cataplexy occurs when you have a sleep attack that is triggered by a strong emotion. This can happen when you are surprised, elated or even intimate with a partner. You may slur your speech or lose control of your limbs, or you may become completely paralyzed.
Narcolepsy with cataplexy is frequently linked to increased weight, sometimes obesity. It is possible to have narcolepsy along with another sleep disorder, such as sleep apnea or REM sleep behavior disorder.