Which sleep disorder is marked by unrefreshing naps?

Hypersomnolence Disorder is characterized by excessive daytime sleepiness and unrefreshing naps. Individuals with this disorder often find that despite napping, they do not feel rested afterward and may still experience significant sleepiness during the day. This persistent nature of sleepiness, even after prolonged sleep or napping, distinguishes hypersomnolence from other sleep disorders.

In contrast, insomnia disorder primarily involves difficulty falling asleep or staying asleep, leading to impaired daytime functioning, rather than unrefreshing naps. Narcolepsy includes not only excessive daytime sleepiness but also other symptoms such as cataplexy and sleep attacks, which are not primarily focused on the unrefreshing quality of naps. Obstructive sleep apnea hypopnea focuses on disrupted sleep due to breathing problems during sleep, resulting in nonrestorative sleep, rather than specifically identifying the nature of naps taken during the day. Thus, the unique emphasis on the experience of unrefreshing naps specifically aligns with hypersomnolence disorder.