Sleep and wakefulness are generally regulated by our brains working with input from our senses and our circadian (pronounced sur-KAY-dee-uhn) clock.
This system pushes us to wake up and remain awake at certain times and pushes us to sleep at certain times. Research has helped us to begin to understand this system at the level of the cells in the brain. More work is needed to understand exactly how the brain, senses, and our body’s clock work in waking and sleeping and what can happen to disturb this cycle. Visit the National Institute of Neurological Disorders and Stroke’s Understanding Sleep page for more information on the sleep cycle.