What is the primary issue associated with REM sleep disorder?

REM sleep disorder is primarily characterized by a person acting out their dreams, which is a significant feature that distinguishes it from other sleep disorders. During REM (Rapid Eye Movement) sleep, most people experience muscle atonia, a temporary paralysis that prevents them from physically acting out their dreams. However, in individuals with REM sleep behavior disorder, this muscle paralysis is absent or incomplete. As a result, individuals may engage in complex movements, such as talking, yelling, or even physically attacking objects or their partners, all while being immersed in their dreams. This disruption can pose safety risks to both the individuals experiencing the disorder and those around them. Understanding this core issue is essential because it highlights the unique nature of REM sleep behavior disorder compared to other sleep-related problems, such as insomnia or narcolepsy, which are characterized by different prominent symptoms.