We all as humans need to sleep in addition to other needs such as food, drink, and oxygen, in order to survive. Sleep is a vital clue to your health condition. Humans spend about 1/3 the time of their lives to sleep.

Most of us already know that getting a good night's sleep is important, but not many are trying to sleep for about 8 hours a night. For many people who have "sleep debt", they have forgotten how it feels "really fresh because enough sleep".

An expert, Dr. Rafael Pelayo, a clinical professor in the sleep medicine division at Stanford School of Medicine, explains the secrets of