What is the cause for nightmares and sleep walking

Nightmares and sleepwalking are associated with different sleep processes, and the transcripts don’t establish one single cause for either.

• Nightmares: One proposed explanation is that the brain is repeatedly revisiting a painful or troubling memory; another is that nightmares reflect a failure to process it. The evidence discussed doesn’t settle which explanation is right. Recurrent nightmares are also associated with PTSD, where emotional processing during sleep may be disrupted. 1 2
• Sleepwalking: It typically happens during deep, slow-wave non-REM sleep, when a person enters a mixed sleep–wake state and carries out routine actions without conscious control. It is not considered acting out a dream. 3 4