The sensation of falling when going to sleep is a common experience - and a doctor has shared that it has a reasonable explanation.

A doctor has explained the cause behind the sudden jerking experienced when falling asleep, why it feels like you're falling and offered tips to prevent it.

On TikTok, Doctor Youn, known as @doctoryoun, enlightened his nearly nine million followers about this frequent phenomenon. Termed Hypnic Jerk, this abrupt reaction can be quite alarming while one is unwinding, yet it is not a cause for alarm.

In his video which has been watched over two million times - and counting - the expert explains: "This is called a hypnic jerk, which is involuntary muscle contractions when you are falling asleep. One explanation is that when your muscles relax as you are falling asleep, your body interprets it as if you are falling."

This could explain why, when it occurs, it indeed feels like we are falling. It is often described as the sensation of plummeting from a great height or stumbling over something. He added: "One way to prevent it is to avoid caffeine or exercising several hours before you go to bed."

According to sleepfoundation.org: "Hypnic is short for hypnagogic, a word that describes the transition between wakefulness to sleep, which is when these jerks occur." The common sleeping contractions often only affect one side of the body, such as your left arm and left leg.

Supporting the expert's opinion, the foundation states that excessive caffeine intake and overexercising can lead to this sensation. It further clarified that insufficient sleep, along with stress and anxiety, can also be contributing factors.

It added: "Hypnic jerks can feel different at various times. They can be strong enough to jolt a person awake and disrupt the process of falling asleep. Other times, they may be so mild that the affected person does not notice them at all — although their sleep partner might.

"Hypnic jerks occur at any age, but are more common among adults. In part, this may be due to the fact that some of their potential causes, such as caffeine consumption and elevated stress levels, are also more common in adulthood."

Should I be concerned about hypnic jerk?

Whilst hypnic jerks can be scary, they are not dangerous, with sleepfoundation.org reporting up to 70 per cent of people experiencing it. It added: "Hypnic jerks can be annoying and disrupt the sleep of you or your partner, but that is typically the extent of their negative effects. While it is possible that a particularly violent jerk could lead to a minor injury, this is not common."

Should I see my GP?

Hypnic jerks are distinct from other movements that can occur while awake or asleep. They happen during the transition from wakefulness to sleep, are swift, and are generally considered benign. If hypnic jerks are the only symptom, a visit to the doctor is probably not needed.

However, the foundation cautions that certain symptoms resembling hypnic jerks might necessitate medical evaluation. If one experiences frequent, ongoing muscle spasms throughout the day that radiate to other areas of the body, this could signify a type of myoclonus different from hypnic jerks.

It said: "These types of myoclonus can be indicators of other medical conditions. If you experience other types of jerking movements during sleep beyond hypnic jerks as you fall asleep, they could be symptoms of periodic limb movement disorder. If you are concerned your muscle jerks are a symptom of another issue, speak to your doctor."