hypnagogic hallucination
Pronunciation: hip-nah-GAH-jik
Vivid, often frightening sensory experiences that occur during the transition from wakefulness to sleep.
Full Definition
Hypnagogic hallucinations are perceptual experiences that occur during the hypnagogic state, the transitional period between wakefulness and sleep onset. These hallucinations can be visual, auditory, tactile, or kinesthetic and are often vivid and realistic, sometimes causing significant distress to patients. They are commonly associated with narcolepsy, sleep deprivation, and certain psychiatric conditions. The term derives from the Greek words 'hypnos' (sleep) and 'agogos' (leading), referring to the state that leads into sleep.
Usage
Usage note: Distinguish from hypnopompic hallucinations, which occur during awakening rather than sleep onset.
In Context
- "The narcoleptic patient experienced frequent hypnagogic hallucinations involving shadowy figures in the bedroom." — Sleep disorder evaluation
- "Hypnagogic hallucinations were documented as part of the narcoleptic tetrad in this case." — Diagnostic report