Synonyms: Idiopathic excessive sleepiness
A rare neurologic disease characterized by an excessive daytime sleepiness with long and unrefreshing naps and/or prolonged and undisturbed nocturnal sleep impaired daytime alertness and/or sleep inertia (ie great difficulty in waking up after sleep) and where other causes have been excluded.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version June 2026
Newly diagnosed with
Idiopathic hypersomnia?
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Advocacy Organizations
Hypersomnia Foundation
The Hypersomnia Foundation engages, informs and champions our global community to improve the lives of people with idiopathic hypersomnia and related sleep disorders.
PWN4PWN Corp
PWN4PWN supports people living with narcolepsy and idiopathic hypersomnia, rare neurological sleep disorders that disrupt daily life. We provide education, practical tools, peer support, advocacy and patient-driven insights to reduce isolation and help our community thrive.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.