Definition
A sleep disorder occurring during deep sleep, accompanied by intense fear, screaming, and sometimes sleepwalking. Usually not remembered. Folk traditions describe it as an entity pressing on the chest.
Related Terms
Sleep Paralysis
A temporary condition where the body cannot move while consciousness is awake during sleep onset or awakening. May be accompanied by hallucinations and fear. Culturally associated with 'the nightmare' or incubus.
NREM Sleep
Non-REM sleep stages. Consists of three phases: light sleep, medium-depth sleep, and deep sleep. Dreams can occur in these stages but are typically less vivid and shorter.
Nightmare
Bad dreams that evoke intense fear, anxiety, or terror, usually waking the person. They occur during REM sleep and are typically remembered in detail. Can be linked to stress, trauma, and medications.