Narcolepsy Causes

Medically reviewed by:

Dr Dan Bunstone - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

While the causes of narcolepsy have become better understood in recent years, there are still a lot of things we don’t know about it. It’s become easier to diagnose and manage the symptoms, but working out what has caused it in the first place can be a challenge.

Our online doctors will ask you lots of questions during your consultation to try and work out what could be causing your symptoms. They can refer you to a specialist for further tests to confirm this. Working out the cause of your narcolepsy can help ensure you get the most effective treatment.

Here are some of the best known causes of narcolepsy.

Orexin (also known as hypocretin) is a brain chemical that regulates sleep. When you’re awake, it increases activity in certain parts of your brain. This helps you stay alert and stops you from falling asleep.

In some people with narcolepsy, the neurons that produce orexin haven’t produced enough of it. This causes the person to slip into the REM stage of sleep.

The chemical imbalance could also be a reason for symptoms such as cataplexy and sleep paralysis. It’s actually perfectly normal for your muscles to relax and even enter a state of paralysis during sleep. In narcoleptics, this can happen when you’re awake.

The level of orexin in your brain can also affect the likelihood of experiencing these symptoms. People who have narcolepsy with cataplexy are likely to have more neuron damage than those who suffer narcolepsy without cataplexy.

Since orexin was discovered in the late 1990s, doctors have looked at what causes low levels of it and triggers the symptoms of narcolepsy.

There is a certain genetic marker that’s thought to increase a person’s likelihood of getting narcolepsy. However, not everyone with this marker will develop the condition and studies have disagreed on whether it’s hereditary.
A small number of cases among children were linked to the Pandemrix vaccine, that was used during the swine flu epidemic of 2009-10.
Studies have shown that narcoleptics have raised levels of antibodies, suggesting that certain bacterial infections might be behind the damage to neurons that produce orexin.
Alternatively, your immune system might be wrongly attacking healthy orexin-producing neurons.
Some people find that their response to stress is to fall asleep. In fact, both narcolepsy and cataplexy can both be triggered by an outburst of a range of emotional responses, including laughter, anger and fright.
An irregular sleep pattern can sometimes trigger narcolepsy. This can also be a factor in a number of other sleep disorders.

When a doctor finds an underlying cause for your narcolepsy during their diagnosis, this is known as secondary narcolepsy. Treating this underlying cause can help your symptoms improve.

Dr Dan Bunstone - Medical Officer

Low level of orexin

What triggers narcolepsy?

Secondary narcolepsy

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