Sleep has a vital role in brain function and cognitive performance. A person’s circadian rhythm is determined by the body’s internal clock, which controls the timing of hormone release, metabolic processes, and various biological activities throughout the day. There are two stages of sleep, non-REM sleep and REM sleep, which typically occur about 90 minutes apart. One cycle lasts for about 90 minutes, with 5-6 cycles per night.
The average person goes through about four sleep cycles each night. This means that the brain moves through different stages of sleep, which can be categorized as light, deep, and REM (rapid eye movement) sleep. During REM sleep, dreaming typically occurs. As the night goes on, the duration periods of REM sleep increases–this is why dreams seem to get more vivid or scary later at night.
A good night's sleep is essential for our bodies to heal themselves. According to the National Sleep Foundation, well-rested people are less likely to partake in risky behaviors, be hostile or irritable during the day, or have mood swings. Lack of sleep can also lead to other health issues such as diabetes and obesity. It is important to make sleep a priority by dedicating time to it daily and creating a routine that works best for you.
A normal person needs 7-8 hours of sleep a day, and that is the recommended amount. The average person is sleeping for approximately 1/3 of his or her life. Sleep deprivation can lower a person's immune system, cause them to gain weight, and even cause death.