Hypersomnolence Disorder

Posted byRatel Health
Evidence-based mental health content, reviewed by psychologists and psychiatrists
Attention-Deficit/Hyperactivity Disorder (ADHD)Autism Spectrum DisorderBipolar I DisorderPost-Traumatic Stress DisorderObsessive-Compulsive Disorder

Hypersomnolence Disorder

Medically reviewed · Ratel Health editorial team · Sunday, 16 August 2026

A sleep disorder involving excessive sleepiness despite a main sleep period lasting at least seven hours.

Overview

Hypersomnolence disorder involves excessive sleepiness despite a main sleep period of at least seven hours, along with recurring periods of sleep, prolonged nighttime sleep, or difficulty being fully awake after abrupt awakening.

Signs and Symptoms

Symptoms can include unintended lapses into sleep during the day, non-restorative sleep of nine or more hours, and significant difficulty achieving full alertness upon waking. Experiencing one or more of these symptoms does not necessarily mean that a person has this condition. Diagnosis requires an appropriate clinical evaluation.

Causes and Risk Factors

The exact cause is not fully understood. It is associated with disruptions in brain systems that regulate sleep and wakefulness.

Diagnosis

A diagnosis should be made by a qualified healthcare professional following a comprehensive clinical assessment. Clinicians may use established diagnostic frameworks such as DSM-5-TR and/or ICD-11 as part of a comprehensive assessment.

Treatment

Treatment depends on the individual’s symptoms, clinical history, severity, age, co-occurring conditions, and other relevant factors.

Psychotherapy

Behavioral strategies, such as scheduled naps and consistent sleep timing, may help manage symptoms.

Medication

Certain wake-promoting medications may be considered to help manage excessive daytime sleepiness. Medication decisions should be made with a qualified prescribing healthcare professional. Do not start, stop, or change a prescribed medication based solely on information on this page.

Living With Hypersomnolence Disorder

Consistent sleep schedules and caution with activities requiring sustained alertness, such as driving, are important considerations.

When to Seek Professional Help

Professional evaluation may be appropriate if symptoms persist, worsen, cause significant distress, or interfere with work, school, or relationships.

Outlook

Symptoms can be chronic, but many people find meaningful symptom control with treatment.

Related Conditions

Narcolepsy

A sleep disorder involving recurrent, irrepressible periods of excessive daytime sleepiness, often accompanied by sudden loss of muscle tone (cataplexy).

Kleine-Levin Syndrome

A rare sleep disorder involving recurrent episodes of excessive sleepiness lasting days to weeks, often with cognitive and behavioral changes, separated by periods of normal functioning.

Insomnia Disorder

A condition involving persistent difficulty falling asleep, staying asleep, or achieving restful sleep, causing distress or impairment.

Medical Information Disclaimer

Ratel Health provides general educational information and does not provide medical diagnosis, treatment, or individualized medical advice. Information on this page is not a substitute for evaluation or care from a qualified healthcare professional. Do not use this information to diagnose yourself or another person, or to start, stop, or change treatment or medication without consulting an appropriately qualified healthcare professional.

References

  • American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).
  • National Institute of Mental Health.
  • U.S. Food and Drug Administration.
  • World Health Organization. International Classification of Diseases, 11th Revision.