In extreme cases of hypersomnia, people have been reported to sleep up to 18 hours a day, and they may have difficulty with normal social relations.

• 但这种症状可能会相当严重。极端的嗜睡症病例中，曾有纪录显示患者一天能睡上 18 个小时，因而无法拥有正常的人际关系。