Narcolepsy Causes, Facts, and Symptoms

Narcolepsy is a chronic sleep disorder that causes excessive drowsiness and sleep problems in adolescents and adults. It causes sudden sleep attacks. Typically this happens when you’ve been inactive for any time. You may think that this is limited to job and lifestyle habits. And while it’s true that sleep attacks can happen under those conditions, they can also occur while you’re in school or even driving! 

If you have this condition, you may find it easy to fall asleep, even for short periods. You may also wake to feel rested and refreshed. But that feeling is temporary; within a few hours, you start to feel very sleepy. 

The Basis of Narcolepsy

There are three types of narcolepsy. Their signs and symptoms differ slightly. Also, the cause varies depending on the type you have.

Narcolepsy Type 1

Type 1 is the most common form. Your brain produces different cells that communicate with each other and are responsible for bodily functions and behaviors. 

Narcolepsy happens when there’s a sudden or drastic loss of proteins in those cells. These proteins are what regulate our sleep-wake cycles. Thus, this deficiency causes sleep dysfunctions.

Signs and Symptoms
  • Excessive daytime drowsiness.
  • Chronic sleepiness with irresistible sleep attacks.
  • A sudden loss of muscle tone, brought on by strong, positive feelings.
  • Abnormal sleep patterns.
  • Hallucinations before falling asleep. 
  • Memory loss.
  • Poor concentration.
  • Blurry vision.

Narcolepsy Type 2

Type 2 looks similar to type 1 narcolepsy but with slight differences. One is that type 2 occurs without limb paralysis. Next, we don’t know why type 2 narcolepsy happens. Some people have the same protein deficiency as type 1, but others don’t. Different theories explore connections and offer some possibilities. 

Genetic and Environmental Causes

We know that a genetic predisposition exists. This means that if you have an immediate familial history, your risk for it is 10-40% greater than someone without that connection. 

There’s a strong connection between head injuries, like brain trauma and stroke, and narcolepsy. We don’t know how this happens. However, it’s believed that brain injuries damage different regions that affect your sleep pattern and sleep symptoms. 


Research suggests a connection between certain infections and narcolepsy. Specifically, streptococcal and influenza A infections. Also, the H1N1 vaccine was linked to increased cases of childhood and adult-onset narcolepsy. We don’t know how this happens, but it’s believed that genetics and environmental factors play a role in this. 

Autoimmune Causes

Recently, narcolepsy was described as an autoimmune disorder. This belief begins to explain neuron-producing protein loss. Also, children who develop this condition after an infection or a vaccine may have underlying immunological issues or conditions.

Secondary Narcolepsy

Medical or neurological conditions can cause excessive daytime sleepiness and even muscle paralysis that people with type 1 get.