That “falling” feeling has a name
What you’re experiencing is most likely something called a hypnic jerk (also known as a sleep start).
A hypnic jerk is a sudden, involuntary muscle contraction that happens as you are falling asleep. It often comes with a vivid sensation of falling, tripping, or being startled.
It can involve:
A sudden twitch in the arms or legs
A full-body jolt
A feeling of dropping or losing balance
A brief flash of dream-like imagery (like stumbling or falling)
Even though it feels real, it is not an actual fall. It is a brain-body mismatch happening during the sleep transition.
What’s actually happening in your brain
To understand why this happens, it helps to look at what your brain is doing as you
fall asleep.
Sleep is not an instant switch. It is a gradual process where your brain moves through different stages.
As you begin to drift off:
