Rare 'Sleeping Beauty Syndrome' Causes Weeks of Extreme Hypersomnia

Sleeping Beauty syndrome: 'For a week, I slept 15 to 20 hours out of every 24'

This extremely rare condition, also known as Kleine-Levin syndrome (KLS), mainly affects boys. It is characterized by episodes of massive hypersomnia lasting one or more weeks, often accompanied by cognitive and sometimes behavioral disturbances.