The main symptom of hypersomnia is excessive daytime sleepiness (EDS), or prolonged nighttime sleep, which has occurred for at least 3 months prior to diagnosis. Hypersomnia affects approximately 5% of the general population, with a higher prevalence for men due to the sleep apnea syndromes. There are several treatments that may improve patients' quality of life, depending on the specific cause or causes of hypersomnia that are diagnosed.