Hypersomnolence - What is it? Hypersomnolence is recognized as extreme daytime sleepiness even though a quality recommended amount of sleep at night is being obtained consistently. Narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia are all different types of hypersomnolence. One cannot be diagnosed with hypersomnolence until they have experienced the excessive daytime sleepiness symptoms [...]