Hypersomnia is a sleeping disorder categorised by excessive daytime sleepiness (EDS) despite getting adequate or prolonged sound sleep at night. Some people with this disorder may regularly sleep for 9 to 11 hours a day or more and still feel exhausted. Hypersomnia involves feeling unusually tired. Learn about tests used to diagnose hypersomnia and tips for talking to your doctor about excessive sleepiness. Read about excessive daytime sleepiness ( hypersomnia ), a condition that causes you to feel very sleepy during the day, even if you had a good night's sleep. Hypersomnia makes you feel extremely sleepy during the day — even if you get a healthy amount of rest at night.
