ABSTRACT

A combined action of physical, physiological, and psychological conditions affects the mental and physical quality of our sleep. These conditions should, however, not be considered apart from each other, since physical factors can easily influence the mental quality of sleep and vice versa. Furthermore, physiological reactions of the human body are often a response to the physical condition of the body in its environment. As a result, many of the different aspects of sleeping that are described in this chapter are closely related to each other.