Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Hypersomnia ?
    ### Response:
    Hypersomnia is characterized by recurrent episodes of excessive daytime sleepiness or prolonged nighttime sleep. Different from feeling tired due to lack of or interrupted sleep at night, persons with hypersomnia are compelled to nap repeatedly during the day, often at inappropriate times such as at work, during a meal, or in conversation.
    