Sleep is the natural state of rest in which your eyes are closed, your body is inactive, and your mind does not think. There are 5 stages of sleep that follow each other in a cyclical fashion: wake, relaxed wakefulness, light sleep, deep sleep and REM sleep. Sleep is a vital, often neglected, component of every person's overall health and well-being. Sleep is important because it enables the body to repair and be fit and ready for another day. Getting adequate rest may also help prevent excess weight gain, heart disease, and increased illness duration.