Uncovering the Secrets of Sleep: Its Stages, Cycles, and Functions Sleep is a vital part of our lives. It is essential for our physical and mental health. Sleep deprivation can lead to a variety of health problems. We still have a lot to learn about sleep. What are the stages, cycles, and functions of sleep? How much do we know about the science of sleep? In this chapter, let us explore some of the basic things we know about sleep. Stages...