Sleep secrets The Secrets of Life

Sleep is a very complex physiological process, and it is not as simple as some people think. Sleep is divided into stages depending on the depth of sleep, and on the electrical changes recorded from the brain via the EEG device, in addition to other physiological changes. When a person sleeps, he moves from the light sleep stage (or first stage) to the deep sleep stage (fifth stage), during the first hour of it. After that, sleep moves again to the light, non-deep stage, during which the dream period occurs, and this period lasts from 10 - 25 minutes, and thus sleep changes oscillating between the light stage and the deep stage.
Hence the importance of this book, which talks about the types of sleep, its benefits, and the difference between the sleep of normal people, teenagers, or the elderly. It presents some of the symptoms that affect the sleeper, such as snoring, walking, or talking, and provides some of their details in terms of causes and external influences.