Sleep paralysis can be a frightening disorder, with the sensation of being paralysed while awake. It’s the momentary inability to move either just before sleep onset or when transitioning from REM sleep to awakening. During sleep paralysis, people cannot move or speak, though they can open their eyes and they are well aware of their surroundings. This can last from a few seconds to minutes.

In some cases, dream-like activity, known as hypnagogic or hypnopompic hallucinations, can accompany the paralysis. Hypnagogic hallucinations occur when falling asleep, while hypnopompic hallucinations occur when waking up. These hallucinations can be vivid and quite disturbing, and they seem very real to the person. The person may think, for instance, that they are being attacked by someone or something, yet they cannot move. You can imagine how scary that would be.

What’s happening?

During the REM stage of sleep our bodies are naturally paralysed – it’s believed that this is so we don’t act out our dreams. This paralysed state is known as REM atonia. When we move out of REM sleep to awaken, the person typically regains the use of their limbs straight away and can move around as normal. However, for some people REM atonia continues and the person, although awake, cannot move. While they can still breathe, sufferers often have an intense pressure on their chest, giving them a false impression that they cannot breathe. During REM sleep, breathing naturally becomes shallow and the airways are restricted, so when a person feels this, it is quite frightening. They are, however, able to breathe.

Who gets sleep paralysis?

Sleep paralysis can be a symptom of narcolepsy, where the brain is unable to regulate sleep-wake cycles normally, or sleep apnea. It can also occur after a period of sleep deprivation. Stress and anxiety may be linked to a person’s increased risk of sleep paralysis.

Roughly 8 percent of the population suffer from sleep paralysis, though 20-50 percent of narcoleptics may have this disorder.

What can you do if you have sleep paralysis?

It’s important to get checked by a specialist if you have sleep paralysis to rule out any other sleep disorders, like narcolepsy and sleep apnea, which can be dangerous if not treated.

Lowering stress is obviously beneficial. As can sleeping on your back. Research shows that people are three to four times more likely to experience sleep paralysis if they sleep on their back.

If you wake up and find yourself unable to move, concentrate on being able to move a finger or toe. Moving just one muscle will break the paralysis.