Based on the different symptoms of excessive sleepiness, hypersomnia have been grouped as:
1.
Idiopathic Hypersomnia or
Primary Hypersomnia
2.
Recurrent Hypersomnia
Recurrent hypersomnia have been further classified into:
Kleine–Levin Syndrome (KLS)
A rare form of periodic hypersomnia,this sleep disorder is also known by other names such as Critchley's Syndrome, Kleine-Levin-Critchley Syndrome, Kleine-Levin Hibernation Syndrome, Familial Hibernation Syndrome, Periodic Somnolence and Morbid Hunger
Post Traumatic Hypersomnia
Menstrual-Associated Hypersomnia