Sleep Fundamentals || H is for Hypersomnia

Information about the problem of chronic sleepiness known as hypersomnia.

Sleep Fundamentals: What is Hypersomnia?



This post first appeared January 17, 2016 and was updated on July 29, 2017.

What is Hypersomnia?

Hypersomnia is best understood as the opposite of insomnia. Whereas an insomniac struggles to achieve sleep at night, a hypersomniac struggles to stay awake during the day.

It’s estimated that maybe as many as five percent of the population suffers from some form of hypersomnia that is not explained by other medical conditions or lifestyle choices. Hypersomnia usually refers to a symptom (the same can be said for insomnia). However, primary forms do exist along the spectrum of sleep disorders.

The chronic sleepiness that characterizes hypersomnia (also referred to as hypersomnolence) is most frequently referred to as excessive daytime sleepiness (EDS) by sleep health professionals. It happens even when the person has had adequate sleep during the evening and is not remedied by getting more sleep.

People with hypersomnia as a primary complaint may actually be suffering from undiagnosed sleep disorders like Restless Leg Syndrome (RLS) or Obstructive Sleep Apnea. If this is the case, their problems with EDS tend to disappear once they treat their other sleep disorders.

The best way to know if other sleep disorders are causing symptomatic hypersomnia is to undergo an overnight sleep test (an attended nocturnal polysomnogram) as well as a daytime “nap” test known as the MSLT (Multiple Sleep Latency Test).

Sleep disorders that belong in the category of Central Disorders of Hypersomnolence, according to the ICSD-3, include Narcolepsy, Kleine-Levin Syndrome, and Idiopathic Hypersomnia.

All occurrences of hypersomnia can be very difficult to live with, as the need to sleep during the day interrupts the personal, social and professional lives of its sufferers in such a way as to make normal living (including physical activities and relationships) difficult to manage.

2 links on hypersomnia in SleepyHeadCentral:

  1. When we sleep too much (narcolepsy, hypersomnia, and more)
  2. Christa Zielke on the challenges of living with narcolepsy

Links to learn more:

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