When you can’t move: The mystery of sleep paralysis

BY SYLVESTER OJENAGBON

Imagine the scene: you are just starting to wake up, or maybe you are drifting off to sleep. Everything feels normal until you try to move a hand, shift your head, or even just open your mouth to speak. You realise, with a sudden, overwhelming fear, that you are completely paralysed. Although your mind is wide awake, your body feels like a burden.

This is the terrifying reality of sleep paralysis. For centuries, people have struggled to explain this scary experience, and this has led to myths of night demons, witches, and even alien abductions. Today, science offers a much less disturbing, but equally fascinating, explanation: it is a temporary, although dramatic, glitch in your brain’s sleep cycle. It is a mesmerising but frightening intersection of consciousness and physiology.

To truly understand sleep paralysis, we have to look deeply into the brain’s nightly mechanisms. Our sleep is divided into several stages, the most active of which is REM (rapid eye movement) sleep, the phase during which the most vivid dreams occur. During REM, the brain is nearly as active as it is when we are awake. However, to keep you from acting out those complex dreams (for instance, running away from a monster or climbing a mountain), your brain initiates a protective measure called atonia, which is essentially a temporary, natural state of full-body paralysis. This atonia is triggered by the release of powerful inhibitory neurotransmitters, namely GABA and glycine, which effectively “mute” the motor neurones in the spinal cord, preventing signals from reaching your voluntary muscles.

The truth is that sleep paralysis happens when your mind wakes up from the dream state prematurely, but it forgets to turn off this essential atonia switch. You become fully conscious and aware of your bedroom, the sounds outside, and your surroundings, yet your body remains locked down in “sleep mode” by those paralysing chemicals. This experience is surprisingly common; up to one in five people will have at least an episode in their lifetime, usually starting in their teenage years, and although it can happen to anyone, it is slightly more prevalent in adolescents and young adults.

The sheer inability to move or cry out is frightening enough, but what truly makes sleep paralysis a nightmare are the vivid, dreamlike sensations that flood your conscious mind. Because your brain is still partially in a dream state, generating powerful REM imagery, it produces intense hallucinations that feel utterly real. These frightening visions often fall into three chilling categories, and that explains the universality of the old legends.

The first category involves you sensing a dangerous presence in the room or seeing a dark, shadowy figure standing over you or lurking near your bed. This category is known as the intruder and is a common hallucination across cultures, often interpreted as a malevolent spirit or “night terror”. The second is the incubus, or the sensation of severe chest pressure. This makes it hard to breathe, giving the feeling that something heavy is pinning you down or actively choking you. It is a physiological hallucination stemming from the body’s shallow breathing during REM sleep, interpreted by the waking mind as a physical assault. The third is the vestibular-motor experience, where you feel as if you are floating, falling, or hovering over your own body, contributing to the feeling of an out-of-body experience or soul separation. 

Now, when these powerful, terrifying hallucinations combine with your inability to move, your brain goes into hypervigilance, and it is no wonder people emerge from the experience shaken, panicked, and convinced they have just battled a supernatural entity. This extreme fear is amplified by the fact that the paralysis itself prevents the brain from executing the normal fight-or-flight response.

The question is: Why does this “glitch” happen? While the exact cause of any specific episode is difficult to pinpoint, scientists have identified several major risk factors, and they all revolve around disrupting your natural sleep cycle. The number one trigger is simple sleep deprivation. You are also at higher risk if you have irregular schedules, which is common in shift workers, military personnel, or frequent travellers experiencing jet lag, because your body’s internal clock, or circadian rhythm, is constantly struggling to keep up. Even small, habitual factors contribute: sleeping on your back, the supine position, is consistently linked to a higher frequency of sleep paralysis, maybe because it can worsen other breathing issues.

Apart from lifestyle, high stress and anxiety are major contributors. When your mind is under chronic pressure, it struggles to manage its systems, including the complex routine of falling asleep and waking up. This strong link explains why sleep paralysis is also associated with conditions like post-traumatic stress disorder, generalised anxiety disorder, and depression. In some cases, sleep paralysis is a major symptom of a deeper sleep disorder, most notably narcolepsy, a chronic neurological condition involving an overpowering urge to sleep and abnormal manifestations of REM cycles. The fact that the condition often runs in families also suggests a definite genetic predisposition.

The good news is that sleep paralysis is not physically dangerous, and you can take proactive steps to reduce its frequency and lessen its severity. First, you must prioritise excellent sleep hygiene. Aim for the recommended number of hours of sleep (a consistent 7 to 9 hours) every night. And perhaps the single most important change is to maintain a regular sleep schedule. Go to bed and wake up around the same time every day, even on weekends, to stabilise your internal clock. You should also optimise your sleep environment by making sure your bedroom is dark, quiet, and cool, and consciously reduce the consumption of stimulants like caffeine and alcohol close to bedtime. If you find yourself sleeping on your back frequently, placing a pillow behind you or even sewing a tennis ball into the back of your pyjamas can help train you to sleep on your side.

Then, the moment you recognise that you are experiencing sleep paralysis and not a real attack, focus your entire mental energy on moving one tiny, non-paralysed muscle, a technique known as somatic-tactile awareness, instead of struggling against an immovable body. Since the muscles controlling eye movement and breathing are not part of the atonia, focus on trying to rapidly flick your eyeballs from side to side or on trying to make a tiny movement with a finger or toe. Sometimes, this small breach in the paralysis can be enough to “wake up” the rest of your body.

Finally, managing the root causes of sleep paralysis is crucial. Practise relaxation techniques, such as deep breathing or meditation, to calm your mind before going to bed since stress is a major trigger. You, however, need to consult a doctor or a sleep specialist if your episodes are deeply distressing or frequent. By giving your body the consistent, restful sleep it needs and learning to manage your emotional reaction, you can smooth out that tricky transition zone and ensure that when your mind wakes up, your body is ready to follow.

Ojenagbon, a health communication expert and certified management trainer and consultant, lives in Lagos.