嗜睡症状的流行病学研究仍处于初级阶段;大多数流行病学调查关于这个主题发表在过去十年。20多个代表社区研究可以发现。嗜睡的这些研究评估两个方面:过度数量的睡眠和睡眠倾向在日间极度嗜睡清醒。过度的睡眠量指的流行的主观评价睡眠时间大约是4%的人口。日间极度嗜睡一直主要调查的频率和严重程度;症状持续时间已经很少了。日间极度嗜睡发生每周至少3天据报道在4%至20.6%的人口,而日间极度嗜睡严重被报道为5%。在大多数研究中,男性和女性都同样受到影响。睡眠障碍的国际分类,嗜睡症状的本质特征是三个障碍:睡眠不足综合征,嗜睡(特发性、复发或创伤后)和嗜眠症。 Insufficient sleep syndrome and hypersomnia diagnoses are poorly documented. The co-occurrence of insufficient sleep and excessive daytime sleepiness has been explored in some studies and prevalence has been found in around 8% of the general population. However, these subjects often have other conditions such as insomnia, depression or sleep apnea. Therefore, the prevalence of insufficient sleep syndrome is more likely to be between 1% and 4% of the population. Idiopathic hypersomnia would be rare in the general population with prevalence, around 0.3%. Narcolepsy has been more extensively studied, with a prevalence around 0.045% in the general population. Genetic epidemiological studies of narcolepsy have shown that between 1.5% and 20.8% of narcoleptic individuals have at least one family member with the disease. The large variation is mostly due to the method used to collect the information on the family members; systematic investigation of all family members provided higher results. There is still a lot to be done in the epidemiological field of hypersomnia. Inconsistencies in its definition and measurement limit the generalization of the results. The use of a single question fails to capture the complexity of the symptom. The natural evolution of hypersomnia remains to be documented.