National Sleep Foundation

Chapter 1: Normal Sleep

Sleep Disorder Classifications

There are many distinct sleep disorders, but most are characterized by one of the following symptoms: “excessive daytime sleepiness, difficulty initiating or maintaining sleep, or abnormal movements, behaviors, and sensations occurring during sleep.”127

There are currently three systems used to classify sleep disorders:

1.      The Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition (commonly known as the DSM-V), published by the American Psychiatric Association, Washington, DC, 2013.128

This system lists 10 “sleep-wake disorders,” conditions (or groups of conditions) that are manifested by disturbed sleep that cause both distressed and impaired functioning during the daytime:

1.      Insomnia disorder

2.      Hypersomnolence disorder

3.      Narcolepsy

4.      Breathing-related sleep disorders, including:

o   Obstructive sleep apnea hypopnea

o   Central sleep apnea

o   Sleep-related hypoventilation

5.      Circadian rhythm sleep disorders, including:

o   Advanced sleep phase syndrome

o   Irregular sleep-wake type

o   Non-24-hour sleep-wake type

6.      Non-REM (NREM) sleep arousal disorders

7.      Nightmare disorder

8.      REM sleep behavior disorder

9.      Restless legs syndrome

10.  Substance- or medication-induced sleep disorder.

2.      The International Classification of Sleep Disorders, Third Edition (ICSD-3), published by the American Academy of Sleep Medicine in 2014.129

ICSD-3 is published in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society. It distinguishes six subcategories of sleep disorders:

1.      Insomnia

2.      Sleep Related Breathing Disorders

3.      Central Disorders of Hypersomnolence

4.      Circadian Rhythm Sleep-Wake Disorders

5.      Parasomnias

6.      Sleep-Related Movement Disorders

3.      The International Classification of Diseases, 10th edition (ICD-10), published by the World Health Organization, Geneva, Switzerland, 1994.130

The ICD-10 system sets aside two areas for sleep disorders: organic (ICD-10 code: G47) and nonorganic (ICD-10 code: F51), but it only includes a few actual sleep disorder diagnoses.


127. Institute of Medicine (IOM) Committee on Sleep Medicine and Research, Colten HR and Altevogt BM (ed.), Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem, Washington, DC: National Academy of Sciences, 2006.

128.  American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Washington, DC: American Psychiatric Association, 2013. See also APA, Sleep-Wake Disorders Fact Sheet, Washington, DC, APA, 2013. On-line at:

129.  American Academy of Sleep Medicine, International Classification of Sleep Disorders, Third Edition: Diagnostic and Coding Manual, Darien, Illinois: American Academy of Sleep Medicine; 2014.

130. World Health Organization (WHO), International Classification of Diseases. 10th ed. Geneva, Switzerland: WHO; 1994.