May also be called: KLS; Familial Hibernation Syndrome; Kleine-Levin Hibernation Syndrome; Sleeping Beauty Syndrome

Kleine-Levin syndrome is a rare disorder that causes a person to sleep excessively. Kleine-Levin syndrome is most commonly found in adolescent males.

More to Know

Someone who has Kleine-Levin syndrome may sleep for up to 20 hours a day, eat excessive amounts of food, or behave in an abnormal and overly sexual way. Other symptoms include irritability, lack of energy, confusion, and hallucinations, and in some cases the condition may be preceded by a flu-like illness.

Symptoms of Kleine-Levin syndrome can come and go, often disappearing for months before recurring. Episodes of Kleine-Levin syndrome can last for a few days or a few weeks, and sometimes people with the disorder can't remember what happened during the episode.

Doctors aren't sure what causes Kleine-Levin syndrome. Some think it has to do with a part of the brain called the hypothalamus that controls sleep, appetite, and other processes in the body that happen automatically. If the hypothalamus malfunctions or is damaged, it could disrupt sleeping and eating patterns.

There is no specific treatment for Kleine-Levin syndrome, but some symptoms may be treated with medications.

Keep in Mind

Most people with Kleine-Levin syndrome are fine and don't have symptoms in between episodes. Typically, the number of episodes will decrease without treatment as kids get older. They should go away entirely in about 8 to 12 years, although some cases may take longer.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.