What Are Dyssomnias? Characteristics, Types, Causes and Treatment

Dyssomnias are disorders that affect our sleep quality, and include insomnia, hypersomnia, narcolepsy, and many more. Learn about the most important dyssomnias, their causes and treatments here.
What Are Dyssomnias? Characteristics, Types, Causes and Treatment
Laura Ruiz Mitjana

Written and verified by la psicóloga Laura Ruiz Mitjana.

Last update: 24 June, 2021

Sleeping well allows us to function well during the day, regain strength, and above all, to enjoy good mental health. But what happens when we don’t rest well? What are the causes? Well, it could be due to sleep disorders such as dyssomnias.

Dyssomnias are defined as ‘alterations that interfere with the quantity and quality of our sleep, making it less restful’. Depending on their nature, we can speak of three groups of dyssomnias. Get to know their characteristics, causes, and treatments here!

What are dyssomnias?

Insomnia is in the group of dysomnias
Insomnia is a dyssomnia.

The International Classification of Sleep Disorders (ICSD) distinguishes three large groups of sleep disorders: dyssomnia, parasomnias (psychological disorders that occur during sleep), and psychiatric sleep disorders.

In the case of dyssomnias, we’re talking about disorders that lessen the quality and quantity of our sleep. In addition, they alter our routine and interfere considerably in our lives, causing us discomfort.

Within dyssomnias, in turn, we find three groups of disorders:

  • Intrinsic sleep disorders
  • Extrinsic sleep disorders
  • Circadian sleep rhythm disorders

Types of dyssomnias

There are three large groups of disorders within dyssomnias. Let’s have a look at which disorders are most relevant within each of them:

Intrinsic sleep disorders

Within this group, we can find a series of disorders with variable characteristics. According to the Classification of Sleep Disorders, they’re the following:

  • Psychophysiological insomnia
  • Idiopathic insomnia
  • Narcolepsy
  • Recurrent or idiopathic hypersomnia
  • Post-traumatic hypersomnia
  • Sleep apnea syndrome
  • Disorder of periodic movements of the legs
  • Restless legs syndrome

We’re going to get to know the characteristics of the most frequent dyssomnias within this group. We can highlight three here: insomnia, hypersomnia, and narcolepsy.


Insomnia is the most common sleep disorder among the general population. According to DSM-5 data, it’s the most prevalent disorder with increasing age, especially in women. It appears in 1-10% of the adult population.

It involves difficulty falling asleep or staying asleep. It also includes cases of early awakenings (before the subject wants to).


Hypersomnia involves excessive daytime sleepiness. This drowsiness is experienced by the person despite them having slept for at least seven hours.

There are also recurring periods of sleep or falling asleep on the same day. In order to diagnose hypersomnia, symptoms must appear at least three times a week, and last for a minimum of one month (according to ICD-10).


Narcolepsy is a sleep disorder that involves recurring periods of an irrepressible need to sleep, to drift off to sleep, or to take a nap. These episodes occur on the same day.

In order to diagnose narcolepsy, according to DSM-5, sleep episodes must occur at least three times a week. Symptoms last at least three months.

Extrinsic sleep disorders

In this second group of dyssomnias, we find extrinsic sleep disorders (those that depend on external or environmental factors). These include the following:

  • Inadequate sleep hygiene
  • Environmental sleep disorder
  • Altitude insomnia
  • Sleep disorder due to lack of adaptation
  • Association disorder in the establishment of sleep
  • Insomnia from a food allergy
  • Syndrome of the nocturnal ingestion of food or drink
  • Sleep disorders secondary to the ingestion of alcohol or drugs

In this group, we can highlight inadequate sleep hygiene. This is very common in people who have stopped taking care of their sleeping habits.

Inadequate sleep hygiene

Inadequate sleep hygiene is considered a dyssomnia in ICSD. It involves practices that work against deep, restful sleep.

These practices vary in each person. For example, they include having irregular schedules (going to sleep at different times each day), taking too much caffeine during the day, not taking care of the sleeping environment (light, temperature…), etc.

Circadian sleep rhythm disorders

In the third group of dyssomnias, we find circadian sleep rhythm disorders. Here is included:

  • Rapid time zone change syndrome (transoceanic syndrome)
  • Sleep disorders in night workers
  • Delayed sleep phase syndrome
  • Advanced sleep phase syndrome
  • Sleep-wake cycle disorder


The causes of dyssomnias can be very varied, depending on the type of dyssomnia. Broadly speaking, we’re talking about:

Temperamental causes

Relationship between anxiety and dysomnias
Anxiety disorders could explain some dyssomnias.

Anxiety, or a worry-centered personality style, produces a neurological phenomenon of neuronal excitement known as arousal. This causes a tendency to repress emotions that can increase vulnerability to different dyssomnias, such as insomnia.

Environmental causes

Poor lighting, poor comfort, high or low temperatures, and high altitude can also be factors that increase the possibility of suffering from dyssomnia.

Genetic and physiological causes

For example, in the case of insomnia, female gender and advanced age are associated with an increased vulnerability for this disorder. In addition, in certain dyssomnias, there’s also a family predisposition (due to genetic inheritance).

Other causes

Poor sleep hygiene can also contribute to dyssomnias. For example, consuming excess caffeine, irregular sleeping practices, etc.


Each dyssomnia should be treated on an individual basis. However, we’re now going to talk about the most valid treatments for the most frequent dyssomnias.

In the case of insomnia – the most frequent dyssomnia – different techniques are used, all of them from the Guide to Effective Psychological Treatments by Marino Pérez (2010):

  • Progressive relaxation
  • Cognitive restructuring
  • Paradoxical intention
  • Stimulus control
  • Chronotherapy
  • Reduced time in bed
  • Multi-component treatment packages

Different techniques are used for narcolepsy. These include changes in the patient’s lifestyle, sleep hygiene, the scheduling of short daytime naps and nighttime sleep periods, as well as changes in diet and physical exercise.

Chronotherapy, light therapy, and sleep-wake rhythm modification (as behavioral treatments) are used in sleep-wake rhythm disorders. But what do these consist of?


The chronotherapy technique is used in sleep-wake rhythm disorders and also in insomnia. It involves exactly synchronizing the different speeds and intensity at which the body functions.

This is achieved by progressively delaying bedtime until the optimal time is reached (3 hours later, over three days). This is a treatment that seeks to re-synchronize the circadian sleep tendencies with the scheduled times for going to bed.

Light therapy

Light therapy consists of intense light stimulation emitted with special lamps, with the aim of synchronizing the endogenous sleep-wake circadian rhythm with the light-dark cycle. Constant exposure to light could be very beneficial.

Sleep disorders involve any type of difficulty related to sleeping. Within these disorders, we find dyssomnias, which, as we have said, are disorders that affect the quantity, quality, and timing of sleep.

There are many types of dyssomnias, although the most frequent are insomnia and hypersomnia. As always, asking for help in these cases will be essential in order to achieve a deep and restful sleep, which is so necessary for us to function properly throughout the day.

“Sleep is the only effective medicine”.


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