The prevalence of narcolepsy is relatively low. However, estimates are likely lower than the actual number of people living with narcolepsy. This is likely due to misdiagnosis and underreporting.

Narcolepsy is a relatively rare sleep disorder that causes symptoms such as excessive daytime sleepiness. It shares symptoms with other conditions, and experts believe it is often misdiagnosed.

The true prevalence of the condition could therefore be higher than what is currently reported.

This article discusses the number of people living with narcolepsy, who gets narcolepsy, symptoms, and more.

A male sleeping with their head on a dining table in a kitchen with tiled flooring. People with narcolepsy may experience excessive daytime sleepiness.Share on Pinterest
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The National Institute of Neurological Disorders and Strokes estimates that around 125,000 to 200,000 in the United States live with narcolepsy.

Other estimates indicate that about 44.3–50 people per 100,000 in the U.S. have the disorder.

The exact number of people with narcolepsy can be difficult to determine. Experts indicate that many cases may go undiagnosed or unreported.

However, the above estimates may be low as they only factor in insured people who actively sought care, which may exclude certain populations.

The number of people living with narcolepsy may vary based on location. For example, a 2022 study noted that an estimated 47 people per 100,000 had narcolepsy across Europe. But in Germany, the incidence was estimated to be about 17.88 people per 100,000.

Narcolepsy can affect anyone and start at any age. The majority of people receive a diagnosis between the ages of 15 and 50 years. The most common ages of diagnosis are 15 and 36.

The condition affects males and females equally.

Scientists are still unclear on the causes of narcolepsy, but they have identified some potential causes and risk factors. These include:

  • Low hypocretin levels: Hypocretin is a hormone that promotes wakefulness and REM sleep. Most people with narcolepsy have very low levels of hypocretin.
  • Autoimmune disorders: Researchers think that environmental and genetic factors may cause the immune system to attack the brain cells that produce hypocretin.
  • Brain injuries: In rare cases, narcolepsy can be caused by traumatic injury, tumors, or diseases in the parts of the brain that regulate REM sleep and wakefulness.
  • Family history: Around 10% of people with narcolepsy report having a close family member with similar symptoms, and clusters can occur in families. However, most cases are sporadic, with no family history.

Symptoms typically start one at a time and can vary greatly between people in terms of severity. The condition:

  • is not progressive
  • may have large gaps between the onset of different symptoms
  • often starts with excessive sleepiness, with other symptoms coming later
  • is a lifelong disorder

Symptoms can vary between people. The symptoms may improve gradually over time, but they typically do not go away entirely.

The most common symptoms include:

Everyone will experience excessive sleepiness, but an estimated 10 to 25% of people will experience one or more of the other symptoms.

There are two types of narcolepsy. Type 1 is narcolepsy with cataplexy. A person with this type either experiences cataplexy or has low levels of a brain hormone (hypocretin).

People with type 2 narcolepsy, or narcolepsy without cataplexy, typically experience less severe symptoms and have regular hypocretin levels in the brain.

In some cases, a person may experience secondary narcolepsy. This can occur due to injury to the hypothalamus, the part of the brain that helps to regulate sleep, or in people with other neurological disorders or sleep issues.

Experts believe that narcolepsy is underdiagnosed. Some note that as few as 25% of people with narcolepsy receive an accurate diagnosis.

In some cases, a person may not seek care for their symptoms. This could also cause lower rates of diagnosed cases.

Proper diagnosis can take years in some cases because doctors mistake narcolepsy for other conditions that have similar symptoms.

Narcolepsy often gets misdiagnosed. According to some experts, healthcare professionals often believe a person may have another psychiatric or emotional disorder.

Many conditions have similar symptoms to narcolepsy, mainly excessive sleepiness. These include:

A person should consider speaking to a healthcare professional if they experience excessive sleepiness or fall asleep while performing activities. They can help rule out possible causes and provide a diagnosis.

Narcolepsy is a relatively rare condition affecting an estimated 125,000 to 200,000 people in the U.S. However, this estimate is likely off, with several experts indicating that numbers are likely much higher due to misdiagnosis and underreporting.