The Importance of Sleep
A good night’s sleep provides a time for the body and mind to rest. During this time, the day’s memories are processed and converted into long-term memory, the brain clears itself of protein debris and cellular waste, and the immune system is strengthened. These processes help you maintain a healthy body, support normal brain function and emotional stability, and keep your senses sharp.
Insufficient or irregular sleep increases the risk for a wide range of physical and mental health problems, including heart disease, obesity, high blood pressure, depression, anxiety, and impaired thinking skills. In children and teens, sleep is crucial for growth and development.
Scientists are only beginning to understand the full complexities of the biological process that is sleep. It’s not the passive state many people once believed, but a powerful process that contributes to almost every aspect of your health.
Most animals, including human beings, sleep in a pattern that is synchronized with Earth’s 24-hour day-night cycle. This natural pattern helps regulate the circadian rhythms that influence your mood, and it works alongside the “sleep drive,” a desire to sleep that grows in intensity the longer you’ve been awake.
During a typical night of sleep, you cycle through four or five different phases, each lasting 90 minutes to two hours. During stages three and four, you spend most of your time in deep sleep. During REM sleep, your eyes move rapidly behind closed lids and your brain waves are similar to those of wakefulness. You also breathe faster and may be partially paralyzed. Dreams are experienced during REM sleep, and they may feel as real as waking life.
Research suggests that the main function of sleep is to refresh your mind and body by removing short-term memories and converting them into long-term ones, and it’s important for emotional stability and learning. It is also necessary for tissue growth and repair. A growing body of evidence indicates that the glymphatic system (a drainage system for the brain) removes toxic byproducts from the central nervous system during sleep, enabling your brain to function well when you’re awake.
Inadequate or irregular sleep raises your risk for a variety of health problems, including heart disease, high blood pressure, diabetes, and obesity. It also reduces your ability to think clearly, react quickly, and concentrate. It can also lead to an increased risk of accidents and a decreased performance at work or school.
Most experts agree that 7 to 8 hours of sleep each night is enough for most adults to function at their best. However, there’s no one-size-fits-all formula for how much sleep each person needs. It depends on the individual’s genetics, age and general health. Children and teenagers need a little more sleep to facilitate growth and development, and older adults need a bit less. The amount of sleep a person needs is also affected by the quality of the sleep. See below for more on improving the quality of your sleep.