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Sleep disorders classification

This article can help you find out more about the most common sleep-related issues. However it is not intended to diagnose yourself for any kind of conditions and is by no means exhaustive.


Insomnia is characterized by difficulty of falling asleep, frequent or prolonged nocturnal awakenings, or finally prematurely waking up with an inability to sleep again.

Basically, taking more than 30 minutes on average to fall asleep, or spending more than 30 minutes awake in the middle of the night, with a sleep duration of fewer than 6.5 hours per night, at least three times a week, represents a problem of insomnia.

There are different possibilities of cause:

  • Temporary insomnia
  • Poor sleep hygiene
  • Psychophysiological insomnia
  • Bad perception of sleep
  • Insomnia related to a mental disorder
  • Insomnia related to a medical condition
  • Insomnia due to a drug or substance


Hypersomnia is characterized by difficulty of staying awake and an important need to sleep (sleeping too much, too often, and / or at any time) when it’s not associated with circadian rhythm disorder, respiratory disorder or any other cause of sleep disorder.


Narcolepsy is a neurological disorder that affects the control of sleep and wakefulness. People with narcolepsy experience excessive daytime sleepiness and intermittent, uncontrollable episodes of falling asleep during the daytime. These sudden sleep attacks may occur during any type of activity at any time of the day. 

The difference with Hypersomnia lies in the fact that Hypersomnia leads to sleep excessive amounts of time and has severe difficulty waking up after sleeping (i.e. excessive sleep inertia). People with narcolepsy frequently do not sleep excessive amounts of time and may find brief naps refreshing. Many people with narcolepsy also experience symptoms related to REM sleep instability such as sleep paralysis.

Sleep disorders in relation to breathing

We know that not only is the amount of sleep important, so is the quality.

A night breathing issue causes poor sleep quality with frequent nocturnal awakenings (conscious or unconscious). There are two main categories of night breathing disorder. 

Obstructive sleep apnea

The most common one is obstructive sleep apnea. It results from obstruction (partial or complete closure) of the breathing airways. The body makes an important effort to breathe, but the air does not pass. About 9 out of 10 people who experience apnea have obstructive sleep apnea. Often these people snore.

Central sleep apnea

During central sleep apnea, no effort to breathe is manifested and no volume of air passes through the lungs: the breath is simply no longer. Central apnea is often accompanied by obstructive sleep apnea. "Pure" central apnea is quite rare. Medical problems such as heart failure, stroke, and kidney failure can cause this central sleep apnea syndrome. It can also be caused by chronic intake of medication and drugs such as opioids, especially methadone, hydrocodone, and morphine.

Circadian rhythm disorders

Circadian rhythm disorders are characterized by a disruption of the biological clock.

Delayed Sleep Phase Disorder (DSPD)

People with DSPD generally fall asleep some hours after midnight and have trouble waking up in the morning. We are not talking about deregulation due to lifestyle but about a genetic cause. The syndrome affects 0.5% of the world's population. If they are allowed to follow their own schedules, e.g. sleeping from 4:00 am to 1:00 pm, their sleep is improved. Attempting to force oneself onto daytime society's schedule with DSPD has been compared to constantly living with jet lag. An adolescent version may disappear in late adolescence or early adulthood; otherwise, DSPD is a lifelong condition. 


Advanced Sleep Phase Disorder (ASPD)

It is a condition in which patients feel very sleepy and go to bed early in the evening (e.g. 6: 00-8:00 p.m.) and wakes up very early in the morning (e.g. around 3:00 a.m.). The syndrome affects 1% of the world's population.

Irregular Sleep-Wake Rhythm

The irregular sleep-wake rhythm is one of the rarest circadian rhythm disorders. Sleep is divided into three or more short-term episodes of sleep, distributed day and night. A fundamental impairment of the biological clock is suspected. The number of hours of sleep acquired in 24 hours is often equal to that of people who have normal sleep patterns however they are suffering from a lack of deep sleep, which is necessary for the body's natural regenerative process.

Non-24-Hour Sleep-Wake Disorder

People who have a Non-24-hour sleep-wake disorder, may find themselves gradually going to bed later every night and waking up later each day. It is very rare, and it occurs because the internal clock is not synced with the day and night cycles. Most individuals with this disorder are blind people. But sometimes people who have normal vision can suffer from it.

Muscular issues during sleep

Muscular issues during sleep are benign motor disorders. Sometimes it can be dangerous because of the external environment around the individual. But most often, these movements are without consequences.

REM Sleep Behavior Disorder

While the person is asleep, she begins to mimic her nightmare/dream and suddenly begins to speak, shout, gesticulate abruptly. These dreams often have a part of violence, and there is a concordance between what the person dreams and what she does.

Periodic Limb Movement Disorder

It is characterized by rhythmic movements of the limbs during sleep. The movements typically involve the legs. Movements occur periodically throughout the night and can fluctuate in severity from one night to the next. These movements are very different from the normal spasms, called hypnic myoclonia, that we often experience initially while trying to fall asleep. It can often cause a partial or full brief awakening, resulting in fragmented sleep. Patients are frequently unaware of these movements.


Sleepwalking is manifested in complex and automatic behaviors, including strolling out of bed, during deep sleep.

Nocturnal cramps

Nocturnal cramps are muscle contractions that affect a muscle or a muscle group. They are usually located on the legs, a calf or a foot. The cramps are very painful and they appear spontaneously and involuntarily. They are usually short and can be repeated several times during the night.

Nocturnal Bruxism 

If you get up in the morning with pain in the jaw muscles or with headaches, you may be suffering from bruxism. Bruxism (grinding and clenching of teeth) is a common behavior; reports of prevalence range from 8% to 31% in the general population. Bruxism can cause dental pain and / or make teeth loose; sometimes even pieces of teeth can come off (fracture). Over time, bruxism can destroy bone and soft tissues surrounding teeth.

Sleep paralysis

Sleep paralysis is a state where a person is aware of his incapacity to move despite his desire to do so. It manifests itself when the person is falling asleep or waking up. This can be accompanied by a hypnagogic hallucination.

Psychological issues during sleep


Hypnagogic hallucinations are an intense and impressive hallucination that occurs at the beginning or end of a sleep period. All the senses can be affected, or only some of them. It is often difficult to distinguish between hallucinations and reality. Hypnagogic hallucinations are often something that is scary.

Confusional arousals

Confusional arousal is an episode of confusional state occurring during or after awakening. The person is disoriented in time and space, is slowed down (slowness of ideas, difficulties of speech, difficulties of understanding ...). She can make incoherent remarks, sometimes related to a dream. His behavior may be inappropriate, inconsistent, or even violent. These episodes can be repeated several times a night. They occur most often during the first hours of sleep and after a nap. There is always complete or almost complete amnesia of the episode.

Nocturnal emission

A nocturnal emission, informally known as a wet dream or sex dream, is a spontaneous orgasm during sleep that includes ejaculation for a male, or vaginal wetness or an orgasm (or both) for a female. These emissions are often associated with erotic dreams.

We remind you that the Circular™ ring is not a medical device and should not be used to diagnose or monitor a pathology.

Amaury Kosman

CEO of Circular, Amaury is all about technology and human capabilities improvement. He is a dedicated marathon runner and loves optimizing his trainings.

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