Sleep, Actually
Sleep, Actually
Narcolepsy and sleep, explained in plain English.
Short definitions, expandable detail, and a searchable glossary — each page carrying its own sources, content type, and review status. Nothing here diagnoses, scores, or treats anything.
20 pages and 42 glossary terms.
Narcolepsy in plain English
Narcolepsy in plain English
What the word actually describes, what it does not, and how the types differ.
Narcolepsy in plain English
A long-term neurological sleep disorder that affects how reliably the brain holds the boundary between sleep and wake.
Reviewed August 8, 2026
Plain-Language NAP ExplanationWhat narcolepsy is not
Clearing away the cartoon version: it is not fainting, not a personality trait, and not simply being tired.
Reviewed August 8, 2026
Sourced Medical EducationNarcolepsy Type 1 and Type 2
Two recognised forms. Type 1 is defined with cataplexy and/or low hypocretin; Type 2 is described without cataplexy.
Reviewed August 8, 2026
Plain-Language NAP ExplanationSleepiness versus ordinary tiredness
Tiredness is low fuel. Sleepiness is pressure to fall asleep. They feel different and respond differently.
Reviewed August 8, 2026
How sleep works
How sleep works
REM, non-REM, stages, and cycles — the vocabulary everything else is built on.
REM and non-REM sleep
Sleep comes in two broad kinds: non-REM (three stages, from light to deep) and REM, where most vivid dreaming happens.
Reviewed August 8, 2026
Sourced Medical EducationSleep stages and sleep cycles
A cycle runs through non-REM stages into REM and repeats several times a night, with REM periods usually lengthening toward morning.
Reviewed August 8, 2026
Measures and tests
Measures and tests
Latency, efficiency, overnight studies, and the MSLT, described without the jargon.
Sleep latency
How long it takes to fall asleep after the lights go out.
Reviewed August 8, 2026
Plain-Language NAP ExplanationREM latency
How long after falling asleep the first REM period begins.
Reviewed August 8, 2026
Plain-Language NAP ExplanationSleep efficiency
The proportion of time in bed that was actually spent asleep.
Reviewed August 8, 2026
Sourced Medical EducationPolysomnography — the overnight sleep study
An overnight recording of brain activity, breathing, heart rhythm, eye movement, and muscle activity while you sleep.
Reviewed August 8, 2026
Sourced Medical EducationMultiple Sleep Latency Test (MSLT)
A daytime test of scheduled nap opportunities, measuring how quickly you fall asleep and whether REM appears.
Reviewed August 8, 2026
Experiences people describe
Experiences people describe
Sleepiness, cataplexy, sleep paralysis, dream-like experiences, fragmented nights, automatic behaviour.
Excessive daytime sleepiness
Persistent, overwhelming daytime sleep pressure that a normal night's sleep does not reliably resolve.
Reviewed August 8, 2026
Sourced Medical EducationCataplexy
A sudden, brief loss of muscle tone while awake, often triggered by strong emotion such as laughter.
Reviewed August 8, 2026
Sourced Medical EducationSleep paralysis
A temporary inability to move or speak while falling asleep or waking, usually lasting seconds to a couple of minutes.
Reviewed August 8, 2026
Sourced Medical EducationDream-like experiences around sleep
Vivid, sometimes unsettling images or sensations while falling asleep (hypnagogic) or waking (hypnopompic).
Reviewed August 8, 2026
Sourced Medical EducationDreaming, Nightmares, and Narcolepsy
Nightmares, dream-like experiences around sleep, sleep paralysis, and dream enactment are related but distinct experiences.
Reviewed August 28, 2026
Sourced Medical EducationFragmented nighttime sleep
Frequently broken nights — a common and often surprising part of a condition associated with daytime sleepiness.
Reviewed August 8, 2026
Sourced Medical EducationAutomatic behaviour
Continuing a familiar activity while partly asleep, with little or no memory of it afterwards.
Reviewed August 8, 2026
Appointments and vocabulary
Appointments and vocabulary
A shared glossary, and a calm way to prepare questions before you go.
Common sleep vocabulary
The words that appear in letters, reports, and appointments — collected in one plain-English list.
Reviewed August 8, 2026
Practical Organisational SuggestionPreparing questions for a healthcare appointment
A calm, practical way to arrive with what you actually wanted to say — and leave with answers you can use.
Reviewed August 8, 2026
Glossary
Common sleep vocabulary, A to Z
Alphabetised and filtered by the search above. A definition tells you what a word means — never what your own result means.
- Actigraphy
- Estimating sleep and wake from movement recorded by a worn device.
- Apnoea
- A pause in breathing during sleep; assessed in an overnight study.
- Arousal
- A brief shift toward lighter sleep or wakefulness, often unremembered.
- Automatic behaviour
- Continuing a familiar activity while partly asleep, with little or no memory of it afterwards.
- Cataplexy
- A sudden, brief loss of muscle tone while awake, often triggered by strong emotion such as laughter.
- Circadian rhythm
- The roughly 24-hour internal cycle influencing sleep and wake timing.
- Common sleep vocabulary
- The words that appear in letters, reports, and appointments — collected in one plain-English list.
- Deep sleep (N3)
- The deepest non-REM stage, usually more prominent early in the night.
- Dream enactment
- Moving, talking, or appearing to act out a dream. Distinguishing it from a vivid dream can require clinical evaluation.
- Dream-like experiences around sleep
- Vivid, sometimes unsettling images or sensations while falling asleep (hypnagogic) or waking (hypnopompic).
- Dreaming, Nightmares, and Narcolepsy
- Nightmares, dream-like experiences around sleep, sleep paralysis, and dream enactment are related but distinct experiences.
- Excessive daytime sleepiness
- Persistent, overwhelming daytime sleep pressure that a normal night's sleep does not reliably resolve.
- Fragmented nighttime sleep
- Frequently broken nights — a common and often surprising part of a condition associated with daytime sleepiness.
- Hypersomnia
- An umbrella term for excessive sleepiness or sleep amount.
- Hypnagogic
- Occurring while falling asleep.
- Hypnopompic
- Occurring while waking up.
- Hypocretin (orexin)
- A brain signalling chemical involved in staying awake.
- MSLT
- Multiple Sleep Latency Test — scheduled daytime nap opportunities, recorded and scored.
- Multiple Sleep Latency Test (MSLT)
- A daytime test of scheduled nap opportunities, measuring how quickly you fall asleep and whether REM appears.
- Narcolepsy in plain English
- A long-term neurological sleep disorder that affects how reliably the brain holds the boundary between sleep and wake.
- Narcolepsy Type 1 and Type 2
- Two recognised forms. Type 1 is defined with cataplexy and/or low hypocretin; Type 2 is described without cataplexy.
- Non-REM sleep
- The three stages of sleep outside REM, from light to deep.
- Polysomnography — the overnight sleep study
- An overnight recording of brain activity, breathing, heart rhythm, eye movement, and muscle activity while you sleep.
- Polysomnography (PSG)
- An overnight, multi-sensor recording of sleep in a sleep centre.
- Preparing questions for a healthcare appointment
- A calm, practical way to arrive with what you actually wanted to say — and leave with answers you can use.
- REM and non-REM sleep
- Sleep comes in two broad kinds: non-REM (three stages, from light to deep) and REM, where most vivid dreaming happens.
- REM latency
- How long after falling asleep the first REM period begins.
- REM sleep
- Rapid eye movement sleep, when most vivid dreaming happens.
- Sleep architecture
- The overall pattern of stages and cycles across a night.
- Sleep cycle
- One pass through non-REM stages into REM, repeated across a night.
- Sleep efficiency
- The proportion of time in bed that was actually spent asleep.
- Sleep hygiene
- General habits around sleep timing and environment. Not a treatment for narcolepsy.
- Sleep latency
- How long it takes to fall asleep after the lights go out.
- Sleep onset
- The moment of falling asleep, as recorded in a study.
- Sleep paralysis
- A temporary inability to move or speak while falling asleep or waking, usually lasting seconds to a couple of minutes.
- Sleep stages and sleep cycles
- A cycle runs through non-REM stages into REM and repeats several times a night, with REM periods usually lengthening toward morning.
- Sleep-related hallucination
- A vivid perception around a sleep-wake transition. The term describes the experience, not its cause.
- Sleepiness versus ordinary tiredness
- Tiredness is low fuel. Sleepiness is pressure to fall asleep. They feel different and respond differently.
- SOREMP
- Sleep-onset REM period — REM appearing very soon after falling asleep, as scored during testing.
- Total sleep time
- The amount of time actually spent asleep during a recording.
- Wake after sleep onset (WASO)
- Time spent awake after first falling asleep.
- What narcolepsy is not
- Clearing away the cartoon version: it is not fainting, not a personality trait, and not simply being tired.
How this hub is labelled
What each label promises
Summarised from the named public health or clinical sources listed on the page.
NAP's own plain-English wording of ideas from those sources.
Anne's personal experience, always labelled as experience — never as medical evidence.
Someone in the community, in their own words. Also experience, also never evidence.
An organising or planning idea. Not treatment, and it makes no health claims.