10 Curious Things that Happen While You Sleep

· November 30, 2015
Many people suffer from bruxism, which is the clenching and grinding of your teeth at night. As a result they may wake up with jaw pain or headaches.

When you close your eyes, you want to basically get a quiet and restful night’s sleep. But actually your body experiences fascinating phenomena while you sleep, which you’ll love to know about. Ready to be surprised?

1. Sudden jerks, jumps and flips

Cat sleeping on a laptop

Surely this has happened to you at some time. You have just fallen asleep and you experience a sudden jerk. This is something so common that we all experience often, and it’s not serious.

This is a phenomenon known as hypnic jerks and it only happens while you sleep. It’s due to the preparation of our body for the changes it will undergo during sleep. Our functions slow down and sometimes the brain interprets this change as a fall. Hence the reaction.

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2. Sleep paralysis

This is something that many people experience. It happens only during the deepest phase of sleep, known as REM (Rapid Eye Movement). These are moments when suddenly we realize that we are dreaming.

We know for example that the horrible nightmare in which we’re engaged is not real, but no matter how much we try to react and move, we cannot. Our arms and legs are paralyzed. This can be very scary, because we’re unable to react even knowing that we are dreaming. That’s when the nightmares are more vivid.

3. Teeth gnashing or grinding

Teeth grinding can happen while you sleep

This is what is known as bruxism. Our teeth gnash due to stress or a misalignment in the jaw. This can make us wake up with a sore jaw or other dental problems.

4. Talking out loud

Has this ever happened to you or to the person sleeping next to you? It’s very common and can sometimes cause problems between the couple. We may call out a word or phrase, or even verbalize a small conversation.

These if something that we forget later and no matter how much others try to make us remember what we’ve said, we are unable to believe it.

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5. Sexual arousal

Couple hugging while they sleep

It’s no surprise, surely you have experienced this on some occasion. Frequently, for example, men experience nocturnal erections, something which is basically a natural and healthy consequence of the circulation and oxygenation of blood, which eventually leads to this sudden erection.

But this effect is not limited to men only. Women may also occasionally experience that feeling of sexual arousal due to some lewd dreams. This arousal occurs because it’s precisely during the night when certain hormones capable of inducing this curious state are secreted.

6. Rapid eye movement

Despite having closed eyelids, our eyes don’t stop moving, especially during REM. The truth is that scientists have not yet reached a consensus as to why this happens. Although many relate it to increased neural stimulation.

This intense brain activity allows us to organize memories, classify information and optimize our memory. Thus the essential biological need to enjoy a peaceful and restful sleep.

7. We are a bit taller at night

Woman getting taller while she sleeps

Surprised? Surely, but we’re only “a little bit” taller, nothing more. This is basically because our spine becomes more hydrated and separates a little at night, thereby allowing the disc space between vertebrae to distance itself slightly, giving us a little more height.

But yes, when morning comes, the discs shrink back to their original position. Interesting, right?

8. The brain detoxifies at night

As you can see, sleep is essential for our health. Especially for the brain, which is incredibly active during these night hours. Besides organizing and classifying information, it helps purify toxins and other harmful elements during these moments thanks to lymphatic system.

It’s in this way, for example, that proteins that protect our brain are optimized, thus avoiding diseases like Alzheimer’s.

9. Growth hormones are secreted in children

Man sleeping with his dog

Children need sleep in order to grow. Their body must release growth hormone or HGH to allow the muscles and bones grow. And keep in mind, it also allows the tissues in adults to regenerate. Therefore, yes, you need to sleep soundly!

10. Lose weight by sleeping!

We know that sleep is an activity that does not offer us any output, but be aware, this doesn’t mean that we don’t use any energy at all. While you sleep, your body performs many basic functions such as detoxifying and eliminating harmful elements, and that’s essential for restoration.

If we don’t detoxify, we’ll retain liquids, become swollen, and our kidneys will not work well. If we don’t sleep properly, a hormone called ghrelin, “the hunger hormone”, will appear. And do you know what this hormone does? It makes us feel hungry. It is worth keeping that in mind.

Takahashi, Y., Kipnis, D. M., & Daughaday, W. H. (1968). Growth hormone secretion during sleep. The Journal of Clinical Investigation. https://doi.org/10.1172/JCI105893

Van Cauter, E., Spiegel, K., Tasali, E., & Leproult, R. (2008). Metabolic consequences of sleep and sleep loss. Sleep Medicine. https://doi.org/10.1016/S1389-9457(08)70013-3

Pelayo, R. (2014). Sleep Paralysis. In Encyclopedia of the Neurological Sciences. https://doi.org/10.1016/B978-0-12-385157-4.00573-X

Khatwa, U., & Kothare, S. V. (2013). Sleep bruxism. In Parasomnias: Clinical Characteristics and Treatment. https://doi.org/10.1007/978-1-4614-7627-6_19

Cuellar, N. G., Whisenant, D., & Stanton, M. P. (2015). Hypnic Jerks A Scoping Literature Review. Sleep Medicine Clinics. https://doi.org/10.1016/j.jsmc.2015.05.010