Why We Don’t Act Out Our Dreams—And What Happens When We Do

Have you ever wondered why you don’t leap out of bed when you’re dreaming of running, flying, or fighting dragons? That’s thanks to a built-in safety feature in your brain. During a stage of sleep called REM (rapid eye movement), when most vivid dreaming occurs, your brain sends signals that temporarily paralyze your muscles. This condition, known as REM atonia, ensures you stay safely in bed, no matter what wild scenarios play out in your mind.

But sometimes, the system glitches. That’s when sleepwalking—and other unusual sleep behaviors—can happen. In these moments, the paralysis mechanism fails to fully engage, allowing a person to move around while still partially asleep. Sleepwalking usually occurs during non-REM sleep, but similar disorders like REM Sleep Behavior Disorder (RBD) can cause people to physically act out their dreams, often with sudden or violent movements.

RBD is more common in older adults and is sometimes linked to neurological conditions like Parkinson’s disease. People with RBD may punch, kick, or even fall out of bed while dreaming, often without remembering the episode. These behaviors can be dangerous for both the sleeper and their bed partner, which is why diagnosis and treatment are important.

Thankfully, treatments such as medications and lifestyle changes can help manage these disorders. Creating a safe sleep environment—like removing sharp objects from the room or padding furniture—can also reduce the risk of injury.

In most people, though, the brain’s sleep-wake system works just fine, and we remain safely still while our minds wander through vivid dreamscapes. It’s a remarkable example of the brain’s ability to protect us—even when we’re not awake to appreciate it.