Why do people sometimes spasm/jump when they are just falling off to sleep?
This falling sensation, together with a body movement known as a “sleep start,” is what doctors and scientists call a hypnic or myoclonic (say: my-eh-kla-nik) jerk, and it usually happens right before going into deeper stages of sleep. Here’s why doctors think the falling feeling and myoclonic jerks happen. When you fall asleep, normally your body temperature goes down and your heart starts to beat just a little slower. This is because your brain signals your body to relax to prepare for sleep. When your muscles are relaxed, you go into the very first stages of sleep, but you’re not sleeping too deeply yet. This brain activity may cause your larger muscles to contract a little bit. In response, another part of your brain will make up a very quick mini-dream to go along with what is happening. You might think this would take a while, but your brain works so lightning fast that it makes up the story almost at the same instant that your muscles jerk. During this light sleep, you can be ea
