Why Do You Jerk Awake When Falling Asleep? Here's What It Means, And Why You Do It

Have you ever been happily drifting off to sleep in your warm and comfy bed, only to suddenly jerk awake with your muscles tensed up and your breath heavy? Most of us have had that experience at least a few times in our lives, but have never really known what it is or why it happened. Why do you jerk awake when falling asleep? It turns out that this reaction during sleep is called a "hypnic jerk," and it's actually more common than you think.

According to New York Magazine's The Cut, the hypnic jerk, also sometimes known as a sleep start, involves a sudden increase in muscle activity just as you're starting to doze off, The effect can be quite startling, and can leave you feeling shocked and even gasping for air, even if you don't necessarily know why.

While almost everyone has experienced a jerk like this one, it manifests differently according to each person. Some people just twitch and don't even know that it happened, unless their significant other tells them later. Others actually make a scared-sounding noise — something that usually results from a bad dream or visual component. The common factor is that it happens right while you're on the cusp of a deep sleep.

So why do these hypnic jerks happen in the first place? While experts still don't know the exact cause of these sudden starts, it seems that it's a result of a fight between the system in your brain keeping you awake, and one that helps you fall asleep. As you're transitioning into a calmer state, the sleeping mechanism usually wins out, but the wakeful one sometimes rears back up.

The good news is that sleep starts are not actually harmful, just annoying. While no one likes jerking awake right as you're about to finally fall asleep, the experience isn't actually hurting you.

Plus, there are certain triggers you can avoid to ensure your sleep starts don't worsen. Tobacco, stimulating medication, not getting enough sleep (ironic, right?) and worst of all, caffeine, have all proven to exacerbate these jerks. So lay off the coffee and soda right before bed — and if you still experience a hypnic jerk, rest easy knowing that it's not just you. We all do weird things in our sleep from time to time.

Image: NBC; Giphy