There are few things more pleasant than letting the worries of the day wash away and slipping into a peaceful slumber while tucked up in bed. But sometimes, just as you’re about to nod off, you’re suddenly hit by a sense of falling and your body jerks you back awake again. It’s an alarming feeling, and a confusing one – not to mention a pain when you’re just trying to get a good night’s sleep.
But why does this happen? Dr Amir Khan, who frequently dishes out health advice on ITV’s Good Morning Britain and Lorraine, explained the phenomenon in a video on TikTok.
Dr Khan said: “Have you ever felt you’re falling just as you nod off? That sudden jolt awake is actually called a hypnic jerk.”
Explaining more, he continued: “As you drift into sleep, your muscles relax, and sometimes your brain interprets that as falling. It’s a misinterpretation, so it sends a quick signal to your body to catch you, and that’s why you twitch awake.
“Now, some scientists think it’s an ancient survival reflex, back to when we slept in trees a sudden twitch might have stopped us from actually falling. It’s totally harmless. More common when you’re stressed, have caffeine late, or you’re just super tired.”
Assuring viewers the phenomenon is “totally normal, totally harmless”, he concluded: So next time it happens, don’t panic. It’s just your brain being quirky.”
What is a hypnic jerk?
A hypnic jerk, short for for hypnagogic jerk, is a sudden, involuntary muscle twitch that happens as you’re transitioning from being awake to sleep, according The Sleep Foundation. The organisation adds 70 per cent of people experience them at some point.
The Sleep Foundation says: “Also known as a sleep twitch, myoclonic jerk, or night start, it often feels like a jolt, a falling sensation, or a sudden kick from your own body. These movements usually affect one side of the body, like an arm or leg, and may be accompanied by a brief dream or startled feeling.”
The organisation added: “Researchers don’t know for certain what causes hypnic jerks, but there are some theories. Hypnic jerks and other types of myoclonus (involuntary muscle twitching) start in the same part of your brain that controls your startle response.
“When you fall asleep, it’s suspected that a misfire sometimes occurs between nerves in the reticular brainstem, creating a reaction that leads to a hypnic jerk. For example, it may be that when your muscles relax completely, even though this is a normal part of falling asleep, your brain mistakenly assumes you’re really falling and reacts by twitching your muscles. It may also be possible that hypnic jerks are a physical reaction to the dream-like imagery that accompanies them.”
The organisation added doing the following things may reduce hypnic jerks:
This story originally appeared on Express.co.uk
