The [Detailed] Sleep Terminology

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Sleep Terminology

We have all been there – tossing and turning at night, desperately trying to fall asleep but our minds just won’t shut off.

It can be frustrating not understanding why we can’t sleep or what exactly is going on with our bodies when we finally drift off.

But when you go to the doctor you have to describe and discuss your sleeping problems – and sometimes you have to speak and understand medical lingo.

You asked for a Sleep Glossary so here is the Sleep Glossary.

Sleeping Terminology

To help you out, we put together a comprehensive sleep terminology – a list of common sleep terms, definitions and meaning of medical sleep terms you might come across so that next time you have insomnia, you can sound like a pro when discussing it with your doctor.


Apnea is a medical condition in which a person stops breathing for a short period of time. Apnea can be caused by a number of factors, including obesity, asthma, and sleep apnea. Apnea can lead to a number of health problems, including heart disease, stroke, and type 2 diabetes.

  1. Obstructive sleep apnea is the more common type of apnea, characterised by repeated episodes of shallow breathing.
  2. Central sleep apnea is less common and is caused by blockages in the upper airway, leading to interruptions of breathing.

Advanced Sleep Phase Syndrome (ASPS)

ASPS is a sleep disorder that causes an advanced sleep phase. There are two types of ASPS: obstructive sleep apnea and central sleep apnea. The Apnea-Hypopnea Index (AHI) is a measure of how many pauses in breathing per hour a person has.

Altitude Insomnia

Altitude insomnia is a sleep disorder that occurs when a person goes to higher altitudes. It is characterized by problems sleeping in the initial, middle, and terminal phases. Insomnia can be primary or secondary, and can be caused by other health conditions or the side effect of medication.


Arousal refers to the breaking of the sleep architecture, which can lead to wakefulness and parasomnia. Arousal is a normal process which can be disturbed in some cases by sleep disorders. Arousal disorders can include sleepwalking, sleep terrors and confusional arousals.

Biological Clock

A biological clock is a natural, internal process that regulates the sleep-wake cycle and other bodily functions. Biological clocks can be affected by factors such as insufficient bright light exposure. Treatment for a biological clock disorder often includes light therapy.


Chronotypes are the individual differences in activity and alertness in the morning and evening. There are four main types of chronotypes, labelled Lion Chronotype, Bear Chronotype, Wolf sleep Chronotype and Dolphin Sleep Chronotype. Knowing your chronotype can help you better plan your day and use your time efficiently.

Circadian rhythm

Circadian rhythm is the neurologic change that affects how you feel awake or sleepy. It is regulated by chemicals released in your brain in response to a stimulus, such as light. Circadian rhythm affects your daily routine, including when you wake up and go to bed.

Circadian sleep disorders

Circadian sleep disorders are a type of sleep disorder that is caused by a disruption in the body’s natural sleep rhythm. Circadian sleep disorders can make it difficult to fall asleep fast or stay asleep, and can also cause unusual behaviors during sleep. Some examples of circadian sleep disorders include jet lag syndrome, shift work sleep disorder, and delayed sleep phase.

  1. DSPS is the most common type of circadian sleep disorder.
  2. There are more than 100 different sleeping and waking disorders.
  3. Circadian sleep disorders can be caused by changing time zones or by working night shifts.
  4. Disruptions to the sleep schedule can lead to disorders such as irregular sleep-wake syndrome, jet lag syndrome, shift work sleep disorder, delayed sleep phase, and advanced sleep phase.
  5. Disorders can be caused by abnormal behaviors during sleep, such as parasomnias.
  6. Circadian sleep disorders are common in children and can include sleepwalking and sleep terrors.


CPAP is an effective treatment for obstructive sleep apnea. It is interfaced with the patient by way of a nasal breathing mask and generally provides good results for people of all ages. CPAP is most often used to treat mild to moderate sleep apnea, but can be used to treat more severe cases as well. Common questions about CPAP use include: How long will I need to use CPAP? What are the side effects of using CPAP? Will my insurance cover the cost of CPAP?

Deep Sleep

Deep sleep is a stage of NREM sleep characterized by EEG waves that are less than 2 Hz and more than 75 uV. Deep sleep usually comprises 4-6% of total sleep time.


Hypersomnia is a condition that causes a person to sleep too much or feel extremely sleepy during the day. Symptoms of hypersomnia include an overwhelming need to nap, feeling confused when first waking up in the morning, and difficulty waking up in the morning. Hypersomnia can be caused by a health condition, sleep disorders, or certain medicines.


Insomnia refers to a sleep disorder in which individuals have difficulty falling or staying asleep. People with insomnia often experience one or more of the following symptoms: difficulty falling asleep, waking up often during the night, waking up too early in the morning, having unrefreshing sleep, and daytime problems due to poor sleep. Insomnia can occur by itself or with other medical conditions. Insomnia can be short-term or term (chronic insomnia).

Insufficient sleep syndrome

Insufficient sleep syndrome is a condition caused by sleep deprivation. People with insufficient sleep syndrome may experience extreme fatigue and drowsiness during the day. The symptoms of insufficient sleep syndrome vary, but can include tiredness, lack of energy, difficulty concentrating, and irritability.

Jet Lag

Jet lag is a disorder that causes fatigue, insomnia, and other symptoms as a result of rapid air travel across time zones. For example, jet lag can be caused by flying from the east coast of the United States to Europe. The time change can cause sleep patterns to be disrupted and make it difficult to adjust to the new time zone. Jet lag is usually short-term and self-imposed, meaning that it goes away on its own after a few days.

Light Therapy

Light therapy is a treatment that uses exposure to light of a specific wavelength in order to help regulate the sleep/wake cycle. Light therapy is often used to treat seasonal affective disorder (SAD) and other conditions.

There are several benefits of light therapy, including its ability to improve mood, energy levels, and sleep patterns. Additionally, light therapy is a safe and non-invasive treatment option with few side effects.


Melatonin is a hormone that is secreted by the body to help regulate the sleep/wake cycle. Although studies have been inconclusive as to whether taking Melatonin supplements have any real benefit on sleep, there is some evidence that suggests that these supplements may help improve sleep quality.


Narcolepsy is a neurological disorder of sleep regulation that causes people to experience excessive daytime sleepiness and intermittent, uncontrollable episodes of falling asleep during the daytime. Narcolepsy usually begins between the ages of 15 and 25, but can become apparent at any age. Narcolepsy is caused by a deficiency of neurotransmitters in the brain and is classified into two types: primary and secondary. Narcolepsy is treated with medication and/or sleep therapy.


A nightmare is an unpleasant dream that usually occurs during REM sleep. Nightmares can be frightening and may cause waking. nightmares can be different from night terrors, which are less severe and usually occur in non-REM sleep. An example of a nightmare is when a person dreams that they are being chased by a monster.

Night Terrors

Night terrors happen when you rise from slow wave sleep. If awakened during a night terror, the individual is usually confused and does not remember details of the event. Night terrors are different from nightmares, which tend to be remembered.


Nocturia is defined as the act of urinating during the night. This can be caused by a variety of different factors, including sleep deprivation, stress, and certain medications. For example, if someone is sleep deprived, they may have to wake up in the middle of the night to use the restroom.

Obstructive Sleep Apnea (OSA)

Obstructive sleep apnea (OSA) is a disorder that occurs when breathing is interrupted during sleep. The most common type of sleep apnea, OSA is caused by a blockage of the upper airway. Symptoms caused by OSA could include fatigue, snoring, daytime sleepiness, restless sleep, gasping for air, high blood pressure and heart disease.

Sleep Architecture

Sleep architecture refers to the structure and patterns of sleep stages and cycles throughout the night. It is important to understand your sleep architecture so that you can diagnose any sleep disorders or related medical or psychological conditions.

Sleep terrors

Sleep terrors are episodes of intense fear that occur during non-REM, slow-wave sleep. They usually last for about a minute but can last up to 45 minutes. Individuals typically have no memory of the sleep terror. Night terrors are different from nightmares in that if someone is awoken during a nightmare, they usually have some recollection of the details.

Sleep Obstruction

Sleep obstruction is a sleep disorder that affects 25% of the population and is caused by a blockage of the airway. OSA can lead to obesity, diabetes, heart disease, and stroke.

Sleep Debt

Sleep debt is the result of not getting enough sleep over a period of time. This can lead to fatigue, irritability, and decreased productivity. For example, if someone regularly doesn’t get enough sleep, they may start to feel the effects of sleep debt.

Sleep Hygiene

Sleep hygiene is important for overall health and well-being. Poor sleep hygiene can lead to poor sleep quality and quantity, which can in turn lead to health problems.

There are a variety of ways to improve sleep hygiene, including diet, exercise, and proper sleep habits.

Sleep Paralysis

Sleep paralysis is a sleep disorder in which a person experiences unusual sensations while they are asleep. For example, a person may feel like they are being held down or that they cannot move. Sleep paralysis can be a symptom of other medical conditions, such as narcolepsy.

Sleep talking

Sleep talking, also known as somniloquy, is a sleep disorder characterized by talking during sleep without being aware of it. Sleep talking can occur during any stage of sleep, but is most common during REM sleep. It can be a single word or phrase, or a long and complicated monologue. Patients generally have no recollection of sleep talking.


Sleepwalking is a sleep disorder in which people engage in complex activities while in a deep sleep. For example, a person with sleepwalking might get out of bed and walk around, or even drive a car.


Snoring is a noisy process caused by vibrations of the soft palate and the uvula. This can create a rough rattling noise. Snorers may develop obstructive sleep apnea.

Sleep Disorders

Sleep disorders are conditions that prevent a person from getting enough Sleep or from getting quality sleep. Sleep disorders can cause problems with falling asleep, staying asleep, or waking up at the wrong times. They can also cause abnormal behaviors during sleep. Sleep disorders can affect a person’s overall health, safety, and quality of life.

Sleep Inertia

Sleep inertia is a feeling of grogginess that people experience the morning after they have not slept. It is caused by the lack of muscle activity during sleep. For example, someone who slept for eight hours but feels groggy in the morning may be experiencing sleep inertia.

Sleep Interruption

Sleep interruption is when a person’s sleep is interrupted by an unexpected event. This can be caused by sleep deprivation or insomnia. For example, if a person is sleep deprived, they may be more likely to be interrupted by a noise during the night. If a person has insomnia, they may be more likely to have their sleep interrupted by their own thoughts or worries.

White Noise

White noise is a mixture of sound waves that are extended over a wide frequency range. It can be used to mask unwanted noise, and it is especially helpful for people who have trouble sleeping. White noise can help people sleep by providing a consistent sound that can block out other noises. Different types of music can also have different effects on sleep.

What is sleeping?

Sleep is a state of rest for the mind and body as well which is when the body can rejuvenate, heal and repair itself. There are four stages of sleep: deep sleep, light sleep, REM sleep, and wakeful sleep.

Sleeping better is utmost important. Coralablanket works for sharing information about how to sleep better.

What are sleep disorders?

Sleep disorders are conditions which interfere with the normal sleep cycle. Problems staying awake include excessive daytime sleepiness and a problem with the brain. Problems sticking to a regular sleep schedule include a problem with the brain and a difficulty staying on a regular sleep schedule.

Disruptions to a person’s sleep schedule can lead to sleep disorders, such as irregular sleep-wake syndrome, jet lag syndrome, shift work sleep disorder, and delayed phase shift disorder . Parasomnias are abnormal behaviors during which can be very disruptive, including but not limited too: somniloquy (sleep talking), somnambulism (sleepwalking), enuresis nocturna (bed wetting), night terrors, & REM Behavior Disorder characterized by acting out dreams during REM Sleep


ZZZ is an onomatopoeic representation of snoring which indicates that someone is sleeping. So Zzz means sleeping.