The Importance of Sleep

Everyone needs sleep, yet many don’t get enough. A full night’s rest can give you the energy to make the most of your day. It can also help you learn, think creatively and maintain a healthy weight. Sleep is a complex process that involves multiple brain and body functions, and researchers are just beginning to understand it. But what we do know now is powerful: Sleep is a critical factor in overall health, and getting enough of it can help prevent diseases like diabetes, high blood pressure, heart disease and depression.

You may be familiar with the saying “a good night’s sleep puts the world to rights.” This is true, and it applies as much to your mental and physical well-being as it does to your emotional stability. Sleep is a natural state that affects almost every tissue and system in the body, including the immune system, metabolism, heart health and brain function. Those who don’t get enough sleep run a higher risk of developing diseases and can have trouble thinking, learning and making decisions.

Throughout the night, the brain and body go through four cycles of sleep. The first two, referred to as non-REM (rapid eye movement) or light sleep, last about 25 minutes. The next two, called REM or deep sleep, take about 50 minutes. The final stage, known as slow-wave sleep or SWS, takes about 75 minutes. During this time, the brain’s electrical signaling slows, and muscle activity is virtually eliminated. This is the most important stage of sleep, and it’s during this phase that people often dream.

The exact reason why we need to sleep remains a mystery, but research supports several theories. One is that sleep allows the body to reorganize and restructure, while clearing out cell and protein debris that build up during the day. Another theory is that sleep strengthens memories and converts them from short-term to long-term, helping us to retain knowledge and information. Lastly, the glymphatic system clears waste from the brain during sleep.

Scientists have found that the average person requires 7-9 hours of sleep each night. The amount of sleep needed varies, however, and is usually influenced by genetics and age. Babies and young children need more sleep than adults, and older adults typically require less.

During the sleep cycle, your brain sends and receives electrical signals, or impulses, to control your body’s activities. These signals are sent from the thalamus to the cerebral cortex, the area of the brain that interprets your senses and stores short-term and long-term memory. During REM sleep, the thalamus becomes active again, sending the images and sounds that form our dreams. Dreams can feel very real, and some people keep dream journals to help them remember them.