Kleine-Levin Syndrome is a rare sleep disorder. Its characteristics include excessive sleep (hypersomnolence which can reach up to twenty hours per day), compulsive over-eating and a highly uninhibited sex drive. While awake, individuals with KLS can be irritable, demonstrate a lack of emotional response and can be quite lethargic. Confusion, disorientation and hallucinations also accompany the disease. The cyclical effects of KLS may be present for days and weeks and generally taper off in frequency and intensity as sufferers age. While no precise cause has been identified, KLS is suspected to be an inherited autosomal dominant genetic trait. What is possible, is that the KLS symptoms are related to a malfunctioning hypothalamus. It is the purpose of this paper to examine the symptoms, treatment and effects of Kleine-Levin Syndrome on its sufferers.