Plain-language sleep reference
Sleep Glossary
A–Z Reference
Find a sleep word, understand it in everyday language, and check what that word can and cannot tell you about your own sleep.
Health terms explain vocabulary, not whether you have a condition. Each entry shows its source and the date Sleep Manager last reviewed it.
Start here
A quicker way to understand an unfamiliar sleep word
The short definition is enough for a quick lookup. Open a term when you want context, limits, related words, and a source.
Find the word
Search a term or abbreviation, browse A–Z, or choose a topic.
Notice the label
See whether it is an everyday idea, a measurement term, or a health term.
Check the limit
Learn what the word does not measure, prove, or diagnose by itself.
Sleep terms
No matching term yet
Try a shorter word, another topic, or clear the filters to return to all 57 terms.
How to read the labels
Three labels, three different jobs
A label describes how the term is normally used on this page. It does not rank the term or show how serious it is.
Everyday idea
A word commonly used when people discuss sleep, routines, or how waking feels.
Measurement term
A questionnaire, calculation, device estimate, biological marker, or sleep-study measure with a defined method.
Health term
A condition, symptom family, treatment, or clinical word. Reading the definition cannot diagnose it.
Source and safety policy
What “reviewed” means here
Source and update trail
Every entry links to one directly relevant primary or authoritative source. “Entry reviewed” is the date Sleep Manager checked its wording against that source. We also recheck an entry when a source changes or a correction is reported. Report an unclear term or broken source.
When a definition is not enough
Repeated breathing pauses, severe or persistent sleep difficulty, sudden sleep attacks, or sleepiness that makes driving or work unsafe deserve professional attention. Stop driving or hazardous activity safely rather than using a glossary to explain it away.
Privacy
Your search, filters, opened terms, and random term stay in this page only. They are not saved to an account or added to the shared link.
Scope
This reference explains vocabulary used across Sleep Manager. It does not replace a sleep history, examination, validated assessment, sleep study, or advice from a qualified clinician.
See exactly how search, filters, random selection, privacy, and sources work.