Sleep Disorders and Concepts: Definitions, Examples, and Evaluation Methods

breathing-related sleep disorders

Sleep problems caused by interruptions in breathing. Example: obstructive sleep apnea, where the airway collapses during sleep.

circadian rhythm sleep-wake disorders

Sleep problems due to mismatched body clocks. Example: night shift workers struggling to sleep during the day.

disorder of arousal

Abnormal behaviours during sleep without full awareness. Example: sleep terrors or sleepwalking.

dyssomnias

Difficulties with getting enough sleep, falling asleep, or staying asleep. Example: insomnia or hypersomnolence disorder.

hypersomnolence disorders

Conditions involving excessive daytime sleepiness. Example: falling asleep during work despite a full night's sleep.

insomnia disorder

Trouble falling asleep, staying asleep, or getting restful sleep. Example: lying awake for hours despite feeling tired.

microsleeps

Short moments of sleep lasting seconds. Example: dozing off briefly while driving after sleep deprivation.

narcolepsy

A disorder with sudden, uncontrollable sleep attacks. Example: falling asleep suddenly while talking or eating.

nightmares

Frightening dreams during REM sleep that wake the sleeper. Example: vivid dreams of being chased.

parasomnias

Abnormal events during sleep or on waking. Example: sleepwalking, night terrors, or acting out dreams.

polysomnographic (PSG) evaluation

A comprehensive sleep study using brain waves, breathing, and movement data. Example: diagnosing sleep apnea with overnight monitoring.

rapid eye movement (REM) sleep

A sleep stage with vivid dreams, rapid eye movement, and muscle paralysis. Example: dreaming you're flying during REM.

rebound insomnia

Difficulty sleeping after stopping sleep medication. Example: worse sleep after discontinuing sleeping pills.

sleep apnea

Repeated pauses in breathing during sleep. Example: loud snoring and waking up gasping for air.

sleep efficiency

The percentage of time in bed actually spent sleeping. Example: sleeping 6 hours out of 8 in bed = 75% efficiency.

sleep terrors

Episodes of intense fear during sleep, often with screaming and no memory afterward. Example: a child waking in terror but not recalling it.

sleepwalking

Rising from bed and walking around while still asleep. Example: walking into the kitchen at night with no awareness.