memes

So, your brain is basically shutting down the nervous system of your body's musculature. This prevents you from moving around in your dreams. Otherwise everybody would be sleepwalking, it doesn't work right for people that are suffering from that. That's also where dreams of flying or falling come from as well as sleep paralysis, which is basically your brain shutting down your body while you're still conscious. Just before your body is shut down, the electric pathways of the nervous system of your musculature are discharged, which can manifest itself as a jolt through your body, ironically waking you up again.

It is thought to be a safety system from our ape like ancestors. The system is designed to rapidly wake us, and make us latch on, if we start to fall. If you're sleeping in a tree, this could be quite a critical response.

Unfortunately, sometimes, as we are falling asleep, the brain shuts down the senses etc in the wrong order. As our sense of balance shuts down, we can momentarily feel like we are falling. This triggers the previous response. Our muscles twitch fire, to try and latch on to something, along with a burst of adrenaline to get us awake. This is obviously less than ideal, if you are trying to get to sleep, in a nice warm bed.

I believe there are genetic components, but disrupted sleep is the most common cause. Overtiredness, disrupted circadian rhythms, or sleep disrupters (bright or blue light, caffeine alcohol etc) can all make it worse. If they are excessively common, they could be a symptom of a larger, more serious sleep condition (e.g. sleep apnea). Don't stress about them, but don't ignore them either, if they are disruptively common.

I believe this is what it is. https://en.m.wikipedia.org/wiki/Hypnic_jerk

It's got to do with a poor sleep routine mixed with the stress and caffeine that it often comes with.

Cut out caffeine three hours before bed, don't eat too soon before bed, try get into a regular sleep and wake up routine and try get at least 6 hours minimum. And don't go to bed with your phone in your face!

Getting some exercise in the day helps a lot too!