Idiopathic hypersomnia (IH) is a sleep disorder that causes extreme daytime sleepiness, even after a full night's rest. The word "idiopathic" basically means the cause isn't fully known — it's not linked to another condition or medication.
It's a nervous system disorder, and researchers are still figuring out exactly how Show Full Answer
Idiopathic hypersomnia (IH) is a sleep disorder that causes extreme daytime sleepiness, even after a full night's rest. The word "idiopathic" basically means the cause isn't fully known — it's not linked to another condition or medication.
It's a nervous system disorder, and researchers are still figuring out exactly how it develops. Some people with IH may overproduce a substance in the brain that acts like a natural sedative, leading to enhanced sleep-promoting activity. IH is often confused with narcolepsy because both cause excessive daytime sleepiness (EDS). However, IH tends to look a bit different. Common signs include:
- Sleeping 10 to 11+ hours a night
- Still not feeling rested after sleeping
- Severe grogginess or disorientation when waking up
- Taking a long time to fully wake up
- Falling asleep at inappropriate times
Unlike narcolepsy, people with IH typically don't experience cataplexy, sleep paralysis, hallucinations, or unusual REM sleep patterns. As one MyNarcolepsyTeam member shared, even getting the right diagnosis can be a journey: "I'm now getting another sleep study to see if it's narcolepsy or idiopathic hypersomnia."
If there's any uncertainty about a diagnosis, a sleep specialist can help sort it out through testing like a polysomnogram or a Multiple Sleep Latency Test (MSLT).
May 18
Ok because I do suffer all the same symptoms of narcolepsy except for the cataplexy but I do at times have the hallucinations and I have severe daytime sleepiness and have fallen asleep while driving. Is this normal for IH?
May 18
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