You’re just drifting off when suddenly—jolt! Your body jerks awake as if startled. If this has happened to you, you’re not alone. These involuntary twitches, called hypnic jerks, affect up to 70% of adults. But what causes them?
As we transition from wakefulness to sleep, our bodies go through distinct stages. During the initial light sleep phase, muscles relax while the brain’s activity slows down. Hypnic jerks typically occur in this twilight zone between being awake and asleep. Sleep expert Dr. Rafael Pelayo explains it as a neurological misfire—some parts of your nervous system are shutting down while others remain active, causing this startling reaction.
Interestingly, these jerks become more frequent when we’re sleep deprived. That’s because exhausted brains sometimes skip normal sleep stages, going straight from wakefulness into REM sleep. The jerk acts like your body’s alarm system saying, “Hey, we’re missing important steps here!”
While startling, hypnic jerks are completely harmless. If they disrupt your sleep, focusing on consistent sleep schedules and reducing caffeine can help. Think of them as your body’s quirky way of checking if you’re really ready to power down for the night.
