World Sleep Day

Sleep was long considered just a block of time when your brain and body shut down. Thanks to sleep research studies performed over the past several decades, it is now known that sleep has distinct stages that you cycle through during the night in predictable patterns: light sleep, deep sleep and REM sleep.

During sleep, your body works its way through a series of distinct stages to help you process what has happened that day, as well as to prepare for the next. This applies to both body and mind. It is important that your body is allowed to do this properly. How much sleep your body gets and the quality of that sleep are important for this task.

Your brain and body functions stay active during sleep, but your organs behave differently during each sleep phase. For instance, certain stages of sleep are needed for us to feel well rested and energetic the next day (deep sleep), while other stages help us learn or make memories (REM sleep).

You cycle through all sleep stages several times during a typical night, with increasingly longer and deeper REM periods occurring towards the morning.

These are our sleep stages

• Light sleep: First step from awake to falling asleep. Your body calms down and prepares for sleep. It is easy to wake up. Next, your body prepares for deep sleep by slowing further down. Typically covers 50% of your night.

• Deep sleep: Now the body is calm, without any eye movement or muscle activity. It will repair muscles and tissue, stimulate growth and development, boost immune functions, and build up your energy for the next day. Typically covers about 25% of your night.

• REM sleep: During REM sleep, your brain is more active, and dreams occur more frequently. This sleep stage is important to learning and memory. Your brain processes and consolidates information from the previous day and stores it in your long term memory. Typically covers 25% of your night.

In brief, a number of vital tasks carried out during sleep help people stay healthy and function at their best. In contrast, not getting enough sleep can be dangerous — for example, you are more likely to be involved in a car crash if you drive when you are drowsy.

How much sleep do I need?

Sleep needs vary from person to person, and they change throughout your life. Most adults need 7-8 hours of sleep each night. Newborns, on the other hand, sleep between 16 and 18 hours a day, and children in preschool sleep between 11 and 12 hours a day. School-aged children and teens need at least 10 hours of sleep each night.

Some people believe that adults need less sleep as they get older. But there is no evidence to show that older people can get by with less sleep than younger people. As people age, however, they often get less sleep or they tend to spend less time in the deep, restful stage of sleep. Older people are also more easily awakened.