The most common causes of severe sleepiness beginning or progressively worsening in adults are SLEEP APNEA and RELATED BREATHING DISORDERS DURING SLEEP. Idiopathic hypersomnia is excessive sleeping without obvious cause. Idiopathic hypersomnia diagnosis can be explained as follows: One could be chronically sleepy due to either something wrong with sleep that makes it non-refreshing, or a problem with the brain mechanisms which normally should keep one alert whether caused by primary problems within the brain or its chemistry, or by other factors (such as sedating medications or thyroid problems). A 71-year-old male who had suffered from excessive sleeping was admitted to our department for oriental treatment on 7th of July, 2003. He was diagnosed as an idiopathic hypersomnia for excessive sleeping without obvious cause. Initial treatment modalities with administration of "SoonHwanGi1HoBang(循環器1號方)" were not effective. However, after administration of "YukMiGiHwangTang(六味地黃湯)" desirable effects were seen.