Kleine-Levin Syndrome: Symptoms & Signs

Medically Reviewed on 8/26/2020

Kleine-Levin syndrome is a rare disorder characterized by episodes of excessive sleep (hypersomnia), which can be up to 20 hours a day. Adolescent males are the group most frequently affected. The excessive sleep occurs in episodes that come on suddenly, last a few days to a few weeks, and may be associated with flu-like or other symptoms.

Signs and symptoms associated with episodes of Kleine-Levin syndrome in addition to excessive sleep can include

  • excessive food intake,
  • irritability,
  • childishness,
  • disorientation,
  • hallucinations, and an
  • abnormally uninhibited sex drive.

Cause of Kleine-Levin syndrome

Doctors do not understand the cause of the condition, but it may be related to problems with function of the thalamus and hypothalamus of the brain since these areas are involved in controlling sleep.

Other kleine-levin syndrome symptoms and signs

  • Abnormally Uninhibited Sex Drive
  • Childishness
  • Disorientation
  • Excessive Food Intake
  • Hallucinations
  • Irritability


Why do we sleep? See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.