How does sleep paralysis happen?

How does sleep paralysis happen?

Have you ever experienced sleep paralysis? The awareness of being awake but you are unable to move your body. 

It can feel frightening and pretty scary! Sleep paralysis is estimated to affect between 40-50% of people at least once in their lives. Often described as a waking nightmare, people have reported seeing grotesque figures. This has led to its other name - old hag syndrome.


Luckily, you are unlikely to experience this on a regular basis. But it’s worth knowing what to expect and how to cope with it if you do.

What is sleep paralysis?

Sleep paralysis is defined as the temporary inability to move your body when either falling asleep or waking up. It happens in the half-way house between sleep and wakefulness. The loss of muscle control is called atonia It can occur alongside hallucinations and the sensation of being suffocated. So it can be a terrifying experience to have.

Parasomnias

Sleep paralysis is classified as a type of parasomnia. Parasomnias are abnormal behaviours that happen whilst sleeping. They range from mild to severe. Although they tend to be more common in children, many adults experience them too. Here are a few types you might have encountered.

Sleep walking

One of the most widely known parasomnias is sleepwalking. The sleepwalker gets out of bed and moves around. If you encounter a sleepwalker, they may appear unresponsive and ‘out of it’ if you communicate with them. 

Night terrors

Night terrors can cause sufferers to scream out in their sleep. They may kick wildly and appear extremely distressed. On waking, they often have no memory of what caused the terror response. 

Nightmare disorder

We all have bad dreams now and again. Nightmare disorder is much worse. The bad dreams occur more frequently, are extremely vivid and affect sufferers during the day as they relive the experience. It can be related to post traumatic stress disorder (PTSD).

Sexsomnia

Although ‘sexsomnia’ is not the official medical term, it pretty much describes the condition. Sufferers will act out sexual behaviours in their sleep. They can make sexual sounds or try and initiate sex. 

Exploding head syndrome (EHS)

The reality of this condition is not quite as scary as the name. EHS is the perception of loud noises as a person falls asleep or wakes up. The crashing or exploding sound is a type of auditory hallucination.

What does sleep paralysis feel like?

The most common symptoms of sleep paralysis:

  • Inability to move the body on waking
  • Unable to speak or make a sound
  • Visual hallucinations
  • Hearing noises
  • A feeling of pressure on the chest
  • Panic, terror and anxiety

Mild sleep paralysis episode 

Some people experience sleep paralysis as simply being unable to move their physical body. It’s like the brain is awake, but the body is still asleep. This feeling can last for a few moments to a few minutes. Eventually, the body catches on to the idea of being awake and you can haul yourself out of bed. This experience often occurs if you haven’t been getting enough sleep and are feeling sleep deprived.

Severe sleep paralysis episode

For others, the experience of sleep paralysis is absolutely terrifying. Sleep paralysis is that nightmare you are unable to wake up from. Your senses are on full alert. If your eyes are open, you can see. That’s when the hallucinations start. 


Imagine your worst fear…it’s slowly getting closer…you fully sense it…you know it’s coming towards you…but escape is impossible. Despite willing yourself to move with every fibre of your being, you have a horrifying sensation that you are being held down. You can’t even scream.

Can sleep paralysis be… nice?

It’s not all bad news. As episodes of sleep paralysis occur during dreaming, it can trigger a lucid dream. A lucid dream occurs when you become consciously aware that you are in the dream state. So you can literally make your wildest dreams come true. Imagine something nice and transform your experience from terror to terrific.

Does everyone get sleep paralysis?

Sleep paralysis is a relatively understudied sleep disorder. Approximately 8% of people are believed to be affected at some point during their life. Sleep paralysis could be an inherited condition. It is also more likely to affect sufferers with other disorders. 

For example:

  • Narcolepsy
  • Sleep apnea  
  • Stress and anxiety
  • Post traumatic stress disorder (PTSD)
  • Alcohol addiction

It is also said that sleep paralysis is more common if you sleep on your back. 

Cultural interpretations of sleep paralysis

Different cultures describe the experience of paralysis with reference to folklore. For a classic depiction of sleep paralysis, take a look at Henry Fuseli’s 1781 painting, ‘The Nightmare’. Maybe not before bed though. Or if you live on Elm Street…


In the US, sleep paralysis is believed to be caused by an old hag. This terrifying old woman sits on the person’s chest and prevents them from moving. In Japan, episodes are caused by a vengeful spirit sent by a sorcerer. In Brazil, the figure is called the Pisadeira. She waits on the roof ready to jump on people who sleep with full stomachs. That’s one reason to lay off the late night snacks!

How does sleep paralysis happen?

Sleep paralysis happens during REM sleep. This is the dreaming part of the sleep cycle. When you are experiencing REM (rapid eye movement) sleep, your body is paralysed to stop you acting out your dreams. Which - let’s face it - prevents a lot of potentially embarrassing situations!


Sleep paralysis occurs when the natural cycle of REM sleep is disrupted. As this is the active dreaming state, your brain is awake but your body is paralysed. 

How to cope with sleep paralysis

If you experience sleep paralysis regularly, sleep is not something you look forward to. One thing you can be sure of is that it will pass. When you are in the midst of your dark imaginings, know that it will end. Your body will eventually catch up and movement is possible. 


Next time it happens, remind yourself that it will be over. There is an end in sight, even if that doesn’t seem likely during the episode. Some people report that focusing on wiggling fingers or toes is one way they can get their body to wake up. 


To help ease your stress, have a relaxing puff on your Ripple+. Let the soothing aromatherapy wash away your old hag-based worries…