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This content was created by the National Sleep Foundation

How much sleep do we really need? Each of us has a specific sleep requirement. Some people need nine hours every night in order to feel their best while others feel great with just seven. But imagine getting ten or more hours of sleep at night plus a couple of hour-long naps during the day and still feeling sleepy. There can be a number of reasons why this would occur but a sleep specialist would consider the possibility of a condition called “idiopathic hypersomnia,” a serious and debilitating disorder with no known cause.

People with idiopathic hypersomnia may suffer either constant or recurrent episodes of extreme sleepiness. There are other causes of extreme sleepiness, such as narcolepsy, obstructive sleep apnea, movement disorders during sleep, and a variety of medications. Chronic sleep deprivation may also cause extreme sleepiness, but in this case getting extra sleep usually alleviates the sleepiness. This is called paying off a sleep debt. Idiopathic hypersomnia, in contrast, persists even after a sleep debt is paid off.


If you are experiencing extreme sleepiness, you should talk to your doctor about the duration and intensity of your symptoms. Your doctor may refer you to a sleep specialist who will take a complete medical history in order to rule out other conditions that may be involved. You may be scheduled to have a sleep study, in which certain criteria must be present for a diagnosis of idiopathic hypersomnia. They are:

  • Having had symptoms for at least six months that have not occurred within 18 months of head trauma.
  • The absence of medical or mental disease that may account for the symptoms, including other sleep disorders such as narcolepsy or post-traumatic hypersomnia.
  • Normal polysomnography results.
  • A Multiple Sleep Latency Test of less than 10 minutes.


The most common treatments for excessive sleepiness are stimulant medications. However, these drugs are not a substitute for sleep. People with idiopathic hypersomnia often must allow more time in their schedules for sleep than most people, even while using such medications. Here are some additional tips for coping with extreme sleepiness:

  • Take naps whenever possible.
  • Maintain a regular sleep schedule.
  • Avoid alcohol and medications that may cause drowsiness.
  • Talk to your friends, family, and co-workers about your symptoms so that they know what to expect and how to help.

This content was created by the National Sleep Foundation

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