Sleep Glossary

Terms and Definitions So You Can Understand Insomnia and Sleep Disorders

Here are some of the more confusing terms used throughout this insomnia guide:

Apnea

a breathing “event” typically associated with a lapse in breathing, in sleep disorders an apnea is commonly associated with obstructive airway problems.

Benzodiazepines

a class of medications used to treat anxiety, stress, depression and insomnia.

Biological clock

part of your body’s circadian rhythm that runs according to a 24-hour cycle; normally your biological clock is synchronized with the natural world and keenly stimulated to sleepiness or wakefulness by visual light/dark cues.

Bruxism

a sleep disorder characterized by grinding your teeth.

Cheyne-Stokes respiration

named for the doctors that first identified this symptom; a significant lapse in breaths which can be symptomatic of congestive heart failure and stroke, but is key in diagnosing some sleep apneas.

Circadian Rhythm

is the animal world’s 24-hour cycle that synchs with light and dark, or wake and sleep; this elementary explanation also goes on to include a carefully timed cycle for a wide range of biological processes, including energy levels, peak coordination, deep sleep, and body temperature peaks and valleys.

CPAP

Continuous Positive Airway Pressure is a machine based on breathing technology developed for hospital use, but is more commonly applied now to patients with obstructive sleep apnea disorder.

GABA receptor

a neurotransmitter in the brain (gamma-aminobutyric acid) that acts as gatekeeper for melatonin, as it relates to the natural sleep-wake cycle.

Hypersomnia

“hyper” means more, and “somnia” means sleep; together they mean more sleep. If you suffer hypersomnia it means you sleep too much, which can be a secondary symptom of other medical or psychological problems.

Insomnia

a pattern of sleep disturbances, and a set of symptoms often related to more specific sleep disorders or medical conditions. Literally, a lack of sleep or sleep deprivation.

Melatonin

a chemical manufactured in the brain’s pineal gland and stimulated by cues in changes in the natural light. Melatonin levels increase after nightfall, inspiring drowsiness, and decrease after dawn for wakefulness.

Narcolepsy

a sleep disorder characterized by the ability of the patient to fall asleep at any given time and without warning.

NREM

non-REM or non-rapid-eye-movement sleep is a primary part of the sleep cycle. Deep sleep characterized by lack of dreams, lack of eye movement.

Parasomnia

a sleep disorder in which you are involuntarily physically stimulated, leading to insomnia symptoms. Common parasomnias include sleep walking, teeth grinding, and restless legs syndrome, among others.

Pineal Gland

a small almond-shaped gland in the brain responsible for hormone production; melatonin is produced in the pineal gland.

Polysomnogram

a diagnostic test used in sleep labs; measures a variety of physical and neuro activities, including heart rate, blood pressure, brain activity, breathing, eye movement and more.

REM

rapid-eye-movement is that stage of sleep characterized by brain activity and dreaming; light sleep level.

Restless Legs Syndrome

RLS is one of the common sleep disorders and characterized by an uncontrollable urge to move your legs due to symptoms described as “twitching,” “crawling,” “jumping,” and other descriptors.

Serotonin

a neurotransmitter responsible for stimulating a wide range of body functions, including mood.

Sleep apnea

a common sleep disorder characterized by a pause in breathing, or an event; 3 types of sleep apnea include obstructive, central, and combination.

Sleep disorder

a condition defined by a set of signs and symptoms that indicates a drastic disruption in your sleep-wake cycle; over 100 sleep disorders have been identified.

Sleep driving

a symptom of a parasomnia sleep disorder in which a person may go out driving and have no recollection of the experience.

Sleep Hygiene

a therapy devoted to remodeling the sleep and bedtime behaviors and habits in order to appeal to more restful sleep; examples include routine bedtime, elimination of dietary stimulants, improvement in exercise and diet, improvement in sleep environment, etc.

Sleep lab

a medical lab in which sleep specialists study patients’ sleep disorders and sleep disturbances.

Sleep questionnaire

a common tool used by doctors to diagnose insomnia and various other sleep disturbances and disorders.