In the classic fairytale by the Brothers Grimm, a beautiful princess named Aurora pricks her finger on a spindle and succumbs to a century-long sleep \u2014 a spell that could be broken only by a kiss from a handsome prince.\nMany of us grew up with this bedtime story, but you might be unfamiliar with its real-life equivalent. In fact, for people who have been diagnosed with a rare neurological condition called Kleine-Levin Syndrome (KLS), excessive slumber is anything but fiction.\nNot Just Fiction: About Sleeping Beauty Syndrome\nAlso known as Sleeping Beauty Syndrome, KLS is a condition marked by long periods of excessive sleep. It typically affects teenagers, but children and adults can have it, too.\nPeople with Sleeping Beauty Syndrome can sleep up to 20 hours a day; the condition occurs in episodes or cycles that can last days, weeks, or even months. Because of this, many people with KLS are unable to work, attend school, or care for themselves during episodes.\nSleeping Beauty Syndrome Signs and Symptoms\nSymptoms of KLS include:\n\nSleeping most of the day and night\nAbrupt onset, sometimes accompanied by flu-like symptoms\nSpaciness or childishness\nLethargy\nExcessive food intake or food cravings while awake\nIrritability\nDepressed mood\nDisorientation\nHallucinations\nProgressive drowsiness\n\nKLS is most common in adolescent boys: An estimated 70 percent of people with this syndrome are male. People with KLS usually act completely normal between episodes.\nA Challenging Concern: Treating Sleeping Beauty Syndrome\nThere’s still much we don’t know about KLS, but it appears to be related to a malfunction of the hypothalamus and thalamus, the parts of the brain that control appetite and sleep.\nThere are also no diagnostic tests to screen for KLS. If you suspect that you or a loved one might have this condition, your physician will likely ask you about your symptoms and rule out other causes of sleepiness, which can include depression and, in teenage girls, premenstrual syndrome.\nLikewise, no specific treatments exist for KLS. Although stimulant medications may help combat sleepiness, they can increase irritability. Some physicians prescribe drugs such as lithium and carbamazepine to counteract symptoms, but these medications aren’t always effective and can have side effects.\nRELATED: Sleep Paralysis Causes and Prevention\nMost physicians recommend watchful waiting without treating KLS. The frequency and severity of KLS episodes tend to ebb over time.\nLearn more by visiting the UPMC Neurology Services website.