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Start free with EleplanIdiopathic hypersomnia
ORPHA:33208Disease
Also called Idiopathic excessive sleepiness
What it is
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.
Key facts
- Prevalence
- 1-5 / 10 000 (Europe)
- Age of onset
- All ages
- Inheritance
- Unknown
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
ICD-10 codes
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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