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Sleep Disorder - Types, Diagnosis, and Treatment

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Sleep disorders disturb an individual's normal and healthy sleep patterns. They may or may not lead to severe complications.

Medically reviewed by

Dr. Arpit Varshney

Published At February 1, 2023
Reviewed AtFebruary 1, 2023


Any condition that disrupts the normal sleep cycle of an individual can be grouped under sleep disorders. There are around 100 different types of sleep disorders. These disorders can also affect how the individual functions when they are awake.

Sleep is often considered to be the time we heal from day-to-day physical and emotional stress. Several studies have concluded the importance of sleep for a person’s health. The human body works even in sleep to regulate the healthy functioning of the brain and aid in physical healing. As we all know, sleep is vital for children and young individuals as it supports growth and development.

Additionally, inadequate sleep has long-term effects and is linked to aggravating or even causing chronic conditions and diseases such as:

Cardiovascular Disease:

Sleep apnea is characterized by repeated pauses in breathing. At the same time, being asleep has been directly linked to an increased risk of cardiovascular diseases like hypertension, stroke, coronary artery disease, and cardiac arrhythmias (or irregular heartbeats), which suggests some correlation between sleep apnea and cardiovascular diseases.


Lack of sleep has always been linked to depression. Though the relationship between sleep and depression is not easy to comprehend, recent studies have shown a reduction in the symptoms of depression once the underlying sleep issues are fixed, which suggests a clear correlation.


Research has shown that sleep time and quality predict hemoglobin A1c levels. It is an important marker of blood sugar control in Type 2 diabetes, the most common type of diabetes.


The relationship between lack of sleep and increased body weight is more pronounced in children. Sleep is essential for brain development in the formative years, and its deprivation can have consequences. Lack of sleep can also affect the function of the hypothalamus, a brain region controlling appetite and energy expenditure.

Polycystic Ovary Syndrome:

Women with PCOS experience poor quality of nighttime sleep or chronic daytime fatigue. According to research, these could be symptoms of sleep apnea that are exacerbating the patient's condition.

What Are the Types of Sleep Disorders?

Classification of sleep disorders is essential to understand the disorder’s causes, symptoms, and treatment plan. The classification of sleep disorders for diagnosis published in 1979 grouped disorders based on symptoms, which was the first primary classification of sleep disorders. However, due to the system's inability to identify the pathophysiology of sleep disorders, there was a need for more advanced classification systems, which led to the development of the International Classification of Sleep Disorders (ICSD), published in 1990.

This classification further underwent some updates and modifications, leading to the publication of the updated classification ICSD 2, and later in 2014, it was updated again to ICSD 3. It is currently the most widely used and advanced classification for sleep disorders.

The ICSD-3 includes six main clinical divisions. They are:

  1. Insomnia.

  2. Sleep-related breathing disorders.

  3. Central disorders of hypersomnolence.

  4. Circadian rhythm sleep-wake disorders.

  5. Parasomnia.

  6. Sleep-related movement disorders.

What Is Insomnia?

The general definition of insomnia (according to ICSD-3) is “a consistent difficulty in initiating sleep, maintaining duration, consolidation, or quality that occurs even though there is adequate opportunity for sleep and results in daytime functional impairment," which essentially sums up the traits of insomnia as persistent sleep difficulty, adequate sleep opportunity, and associated daytime dysfunction.

What Are the Types of Insomnia?

  • Chronic Insomnia Disorder - The sleep disturbances that have been present for the past three months or longer occur at least three times per week. It follows a long-term pattern of sleep difficulty.

  • Short-term Insomnia Disorder - Also called acute insomnia or adjustment insomnia, usually lasting for a shorter period (less than three months).

  • Other Insomnia Disorders - The cases that come under this category are the ones that complain of the typical features of insomnia but meet the criteria for neither chronic nor short-term insomnia.

How Can Insomnia Be Diagnosed?

  • Laboratory Tests: Thyroid function tests, glycosylated hemoglobin, a complete blood count, a liver function test, and a renal function test can provide insight into the underlying medical condition that might be causing the sleep disorder, which can be used as an initial tool to plan treatment.

  • Sleep Records: Maintaining sleep records for 2 to 4 weeks, including logs of alcohol and coffee intake and daytime sleeping, is an effective way to assess the sleep-wake cycle of the patient. These records can help note various sleep parameters like Total Sleep Time (TST), Sleep Efficiency (SE), Wakefulness After Sleep Onset (WASO), etc.

  • Polysomnography: This multi-parameter test is also called a sleep study. Here, various physiologic parameters are collected when the patient is fully asleep. Even though it is the most reliable diagnostic method, this test is usually only done if more than one type of sleep disorder is suspected.

  • Questionnaires and Self-assessment Scales: This diagnostic method helps give a primary idea about the condition.

What Are the Treatments for Insomnia?

Treatment of insomnia can be classified into two types:


  • Sleep Education-Educating patients about the effects of lifestyle habits on sleep and the effects of sleep on overall health plays a crucial role in controlling such cases. This method cannot be effective against Chronic insomnia since it is an advanced condition, but it can prevent further aggravating instances.

  • Stimulus Control Therapy- It is widely known that avoiding any stimulus can be beneficial in improving the quality of sleep. Late-night snacking, screen time, etc., can contribute to unhealthy sleep patterns. Avoiding such stimulants can significantly improve sleep patterns.

  • Relaxation Therapy-Age-old relaxation techniques like yoga, meditation, and music therapy can reduce stress, which might precipitate insomnia.

  • Cognitive Behavioral Therapy for Insomnia (CBT)- CBT therapy is the most effective and has shown results superior to pharmacological therapy. Cognitive-behavioral therapy can be delivered by a nurse, physician assistant, or even a social worker. This therapy is a summed-up version of all other non-pharmacological treatment options.


Drugs Acting on GABA-A Receptors:

  • Benzodiazepine.

  • Zolpidem.

  • Zaleplon.

  • Eszopiclone.

These drugs act on the GABA receptors and have been used for treating various concerns since all three have different action methods.

Drugs Acting on Melatonin Receptors:

  • Melatonin.

  • Ramelteon.

  • Tasimelteon.

  • These drugs work by acting on the melatonin receptors. It mainly helps with sleep initiation.

Drugs Acting as Orexin Receptor Antagonist:

  • Suvorexant.

  • It helps reduce nighttime awakenings.

Drugs Acting as Histamine-1 Receptor Antagonist:

  • Doxepin.

  • At low doses, it helps improve total sleep time.


Insomnia is one of the most common conditions affecting the modern world. Sadly, it is also the most neglected condition. People often dismiss sleep disturbances as a way of life, only to discover later that they have severe consequences for a person's overall health. Studies show that 10 to 30 percent of the world's population has insomnia, which is most common in urban areas. Therefore, one must note that sleep hygiene should be given priority, and healthy habits should be adopted to live a wholesome life.

Dr. Arpit Varshney
Dr. Arpit Varshney

General Medicine


sleep disorder
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