Have you ever been fast asleep, suddenly woken up by a jolting or falling sensation?

If so, you’re not the only one, as a tweet is gaining a lot of momentum online as people are just discovering that this is called a “hypnic jerk”.

To help answer any other questions people may have about hypnic jerks, Martin Seeley, the CEO and sleep expert at MattressNextDay, has explained what they are, how normal they are, and whether you should be alarmed if you have one.

What are hypnic jerks?

Hypnic jerks are the sudden, involuntary body movements that some people experience just before falling asleep. They can occur at any nighttime, but they’re most common in the early morning.

Hypnic jerks may involve muscle twitches or more complex actions such as a head, arm, or leg jerk. The movements can be minor but sometimes violent enough to wake you up.

The sudden movements typically last only a second or two, but they can be quite startling if you’re not expecting them. Hypnic jerks are common in children and adults, though they’re rarely mentioned in conversation because they’re not considered dangerous or harmful.

How normal are they?

Despite being unsettling, hypnic jerks can be a normal part of your sleep cycle. This is because they are caused by the brain’s attempt to regulate its level of alertness during sleep. During REM sleep (the phase of sleep when dreaming occurs), your body is paralysed except for your eyes and muscles involved in breathing.

This paralysis keeps you from acting out your dreams while you’re sleeping. If you could move freely during this time, you might injure yourself or others around you – not exactly an ideal situation.

To enter into deeper stages of sleep without waking up fully, your brain sends signals down through your spinal cord to relax muscles throughout your body – including those that would normally be active during wakefulness but aren’t needed at this time (such as muscles used for speech). This process allows your body to enter into a deeper state of sleep.

Should you be concerned if you have one?

In most cases, hypnic jerks don’t cause any pain or harm – but they may make you feel alarmed when you suddenly jolt awake with a sudden jerk of your body like you’ve been hit by electricity.

Four ways to fall back asleep after having a hypnic jerk

They can be disruptive if you have them regularly and, therefore, keep waking up in the middle of the night. If this happens to you, you can fall back asleep.

Take some deep breaths

When your body is stressed, it’s harder to relax completely and fall asleep quickly. So if you’re feeling a bit startled about being woken up abruptly, take some deep breaths to help calm down your mind and body. 

Stay off your phone

Whilst you may be tempted to go on your phone to distract your mind, this is the worst thing you can do in the middle of the night. This is because the blue light emitted from your phone can interfere with your body’s production of the sleep hormone melatonin.

In turn, this makes you feel more awake, naturally, making it harder for you to fall asleep. Plus, seeing the time on your phone may stress you out if you need to be awake in a couple of hours.

Make yourself more comfortable

It may seem obvious, but make sure you’re lying in a position that makes you feel comfortable before attempting to drift off again – especially if you’re used to sleeping on your side or stomach.

Carry out a full body scan

If you’re still struggling to sleep, try this meditative technique, a full-body scan. Simply close your eyes and breathe slowly. Next, focus on your face and think about relaxing each of the muscles in your face.

After 30 seconds to a minute, move onto your neck and do the same thing for 30 seconds. Then your shoulders, and then your arms. Essentially, you want to relax every muscle until you reach your feet.