Narcolepsy risk factors: who is more likely to get it

What narcolepsy is

Narcolepsy is a chronic neurological disorder that affects the brain's ability to control sleep-wake cycles. People with narcolepsy may feel rested after waking but then feel very sleepy through much of the day, and many also have broken (fragmented) sleep at night (NINDS).

In a normal sleep cycle, people enter rapid eye movement (REM) sleep, the stage with the most dreaming, after about 60 to 90 minutes. People with narcolepsy often enter REM sleep within 15 minutes of falling asleep, and they can have the muscle weakness or dream activity of REM sleep while they are awake (NINDS).

MedlinePlus Genetics says narcolepsy affects about 1 in 2,000 people in the United States and Western Europe, and that it is likely underdiagnosed, especially in people with mild symptoms (MedlinePlus Genetics).

Two types

• Type 1 (once called narcolepsy with cataplexy): diagnosed either by finding low levels of hypocretin (also called orexin), a brain chemical that helps you stay awake and controls REM sleep, or by cataplexy plus excessive daytime sleepiness on a special nap test (NINDS).
• Type 2 (once called narcolepsy without cataplexy): excessive daytime sleepiness, usually without cataplexy, with less severe symptoms and normal hypocretin levels (NINDS).

Secondary narcolepsy can result from an injury to the hypothalamus, a region deep in the brain that helps regulate sleep (NINDS).

Who is more likely to get narcolepsy

NINDS says narcolepsy affects men and women equally. Symptoms usually begin between ages 7 and 25 but can start at any age (NINDS). MedlinePlus Genetics says it most often begins in adolescence (MedlinePlus Genetics).

Nearly all people with type 1 narcolepsy have very low levels of hypocretin. The causes are not fully understood, but NINDS says current research suggests several factors may work together to cause a lack of hypocretin (NINDS):

• Immune system (autoimmune) problems: when cataplexy is present, the cause is most often the loss of the brain cells that make hypocretin. Researchers believe the immune system attacks these cells because of a mix of genetic and environmental factors.
• Family history: most cases happen in people with no known family history, but up to 10% of people diagnosed with type 1 narcolepsy report a close relative with similar symptoms.
• Brain injuries: rarely, narcolepsy results from a traumatic injury to the parts of the brain that regulate wakefulness and REM sleep, or from tumors or other diseases in the same areas.

Genes

A variation in the HLA-DQB1 gene, called HLA-DQB1*06:02, increases the chance of developing narcolepsy, particularly type 1. Most people with narcolepsy have this variation (NINDS). MedlinePlus Genetics adds that variations in several other genes, many tied to the immune system, have also been linked to narcolepsy, but they probably make only a small contribution to the overall risk (MedlinePlus Genetics).

Infections as possible triggers

NINDS says narcolepsy follows a seasonal pattern and is more likely to develop in spring and early summer, after the winter season when people are more likely to get sick. People with narcolepsy have been found to have high levels of certain antibodies soon after it develops, which points to an immune response to a recent bacterial infection such as strep throat. The 2009 H1N1 flu epidemic was followed by a large increase in new cases (NINDS). Together, NINDS says, this suggests that people with the HLA-DQB1*06:02 variation are at risk of developing narcolepsy after exposure to a specific trigger, like certain infections (NINDS). MedlinePlus Genetics lists strep throat, colds and influenza among the infections that may be involved in people who are at risk (MedlinePlus Genetics).

Symptoms

Once narcolepsy develops, it lasts for life. Symptoms differ from person to person and can improve over time, but they never go away completely (NINDS). The most typical symptoms are (NINDS):

• Excessive daytime sleepiness: everyone with narcolepsy has it. It does not improve even after enough sleep at night and often comes as a "sleep attack," an overwhelming sleepiness that comes on quickly.
• Cataplexy: sudden muscle weakness, often set off by strong emotions such as laughter, fear, anger, stress or excitement. It ranges from slight drooping of the eyelids to a full body collapse, but the person stays fully conscious. Episodes usually last a few seconds to several minutes and are not dangerous as long as the person is in a safe place.
• Sleep paralysis: a brief inability to move or speak while falling asleep or waking up, sometimes with vivid dreamlike hallucinations.
• Broken nighttime sleep and insomnia: waking several times a night for 10 to 20 minutes, which can make daytime sleepiness worse.
• REM sleep behavior disorder: acting out dreams by punching, kicking, shouting or grabbing during sleep.

Untreated narcolepsy can affect emotional well-being, social life and the ability to think clearly, which can affect school and work (NINDS). NINDS says people with narcolepsy are often misdiagnosed with other conditions, such as psychiatric disorders, so it can take years to get the right diagnosis (NINDS).

How narcolepsy is found

A doctor will do a clinical exam and take a detailed medical history, and may ask you to keep a sleep journal of your sleep times and symptoms for 1 to 2 weeks. It is often necessary to see a sleep medicine specialist (NINDS). Two tests done in a sleep disorders clinic are needed to establish the diagnosis (NINDS):

• Polysomnogram (overnight sleep study): records brain activity, muscle movements, breathing and eye movements during sleep, to see whether REM sleep comes too early and to check for other conditions such as sleep apnea.
• Multiple sleep latency test: measures how quickly you fall asleep during the day and whether you enter REM sleep.

Sometimes the hypocretin level in the fluid around the brain and spinal cord is measured, using a sample taken by lumbar puncture (spinal tap) (NINDS).

Treatment and living with narcolepsy

There is no cure, but symptoms can be managed with a combination of medicines and lifestyle changes, and it often takes time to find the right mix (NINDS). NINDS lists wake-promoting medicines, stimulants, certain antidepressants for cataplexy, oxybate medicines and pitolisant (NINDS). In 2026 the FDA approved oveporexton tablets for adults with type 1 narcolepsy, which NINDS describes as the first medicine to treat the full range of type 1 symptoms (NINDS). Talk to your doctor about which treatment fits you.

NINDS says research has shown people with narcolepsy are at higher risk of heart disease and other serious heart problems, so their heart health should be checked regularly by a doctor (NINDS). See heart disease risk factors.

Lifestyle tips from NINDS (NINDS):

• take short, regularly scheduled naps at the times you tend to feel sleepiest
• go to bed and wake up at the same time every day, even on weekends
• avoid caffeine and alcohol for several hours before bed, and avoid smoking, especially at night
• exercise for at least 20 minutes most days, at least 4 or 5 hours before bedtime
• eat a heart-healthy diet and avoid large, heavy meals late in the day
• relax before bed and keep the sleep space cool and comfortable
• take safety steps, especially when driving: avoid driving when sleepy

Cognitive behavioral therapy (CBT), a form of talk therapy, can help people with narcolepsy sleep better and feel less sleepy during the day (NINDS). Under the Americans with Disabilities Act, employers must allow adults with narcolepsy to ask for work adjustments, such as flexible schedules for naps (NINDS).

Common questions

Does narcolepsy run in families?

Usually not. NINDS says most cases happen in people with no known family history, although up to 10% of people with type 1 narcolepsy report a close relative with similar symptoms (NINDS).

At what age does narcolepsy start?

Symptoms usually begin between ages 7 and 25, but they can start at any age (NINDS).

Is narcolepsy the same as insomnia?

No. Narcolepsy is a neurological disorder in which the brain cannot control sleep-wake cycles normally, and its main symptom is excessive daytime sleepiness (NINDS). Many people with narcolepsy also have trouble staying asleep at night, and their sleep may be disrupted by insomnia (NINDS). See insomnia risk factors.