Parasomnias are undesirable behaviors or experiences that occur during sleep, the process of falling asleep, or while waking up. These may include activities like sleepwalking, talking in your sleep, or experiencing nightmares that lead to physical reactions, such as waking up with a racing heart. Most people experience parasomnias at some point in their lives, and while they are typically not harmful, they can be disturbing, frustrating, or occasionally dangerous to the sleeper or their bed partner.
Parasomnias can be triggered by various factors, including sleep deprivation, stress, disturbed sleep (such as from conditions like sleep apnea or restless legs syndrome), or psychological disorders like depression or PTSD. Certain neurological conditions (e.g., narcolepsy, Parkinson’s disease) and medications may also increase the likelihood of parasomnia events. While some parasomnias have clear causes, others may not, and genetic predisposition can also play a role in their occurrence.
Parasomnias are classified based on the sleep stage they occur in, with some taking place during non-rapid eye movement (NREM) sleep, others during rapid eye movement (REM) sleep, and some occurring during transitions between sleep and wakefulness.