What is "nyctophobia"

medical Latin, from nycto- "night" + -phobia "fear." Related: Nyctophobic.

n. A fear of the night, nighttime or darkness.

n. a morbid fear of night or darkness

Nyctophobia is a phobia characterized by a severe fear of the dark. It is triggered by the brain’s disfigured perception of what would, or could, happen when in a dark environment. It can also be temporarily triggered if the mind is unsteady or scared about recent events or ideas, or a partaking in content the brain considers a threat (examples could include indulging in horror content, witnessing vulgar actions, or having linked dark environments to prior events or ideas that disturb the mind).

Despite its pervasive nature, there has been a lack of etiological research on the subject. Nyctophobia is generally observed in children but, according to J. Adrian Williams’ article titled, "Indirect Hypnotic Therapy of Nyctophobia: A Case Report", many clinics with pediatric patients have a great chance of having adults who have nyctophobia.

The word nyctophobia comes from the Greek νυκτός, nyktos, genitive of νύξ, nyx, "night" and φόβος, phobos, "fear". The fear of darkness or night has several non-clinical terminologies—lygophobia, scotophobia and achluophobia.