The Importance of Sleep
If you’re tired, it may be because you’re not getting enough sleep. Most adults need between 7 and 8 hours of rest each night. Sleep is important for cognitive, emotional and physical health. If you have problems sleeping, talk to your doctor about it.
Sleep is a natural process that occurs in most animals and in humans. It’s a unique state of being that helps your body heal and restore itself, and it gives your brain a chance to clear and refresh. It also helps keep your heart healthy, and it makes you less likely to be injured or sick.
Scientists are just beginning to understand why sleep is so important. Several theories exist, including the inactivity theory, which suggests that sleep developed as a way to reduce the risk of predators after dark. Another possibility is that it’s necessary for maintaining the balance of hormones that control your appetite, energy and emotions. The importance of sleep is widely recognized, but research into the topic is ongoing.
A recent study found that people who don’t get enough sleep have more trouble learning and remembering. They have difficulty thinking and concentrating, and they have more trouble focusing their attention on tasks that require emotional involvement. Insufficient sleep can also have an impact on how well you perform emotionally and socially.
You don’t have to get all of your sleep in one stretch at night, though that’s a common practice for many people. Throughout history, many cultures have embraced the practice of taking naptime during the day or splitting nighttime sleep into two periods. Some examples include the siesta in Spanish-speaking countries and the inemuri (a short workplace nap) in Japan.
During sleep, the brain goes through four stages that last different lengths of time, from 90 minutes to two hours. The most active stage is called rapid eye movement, or REM sleep. It’s named for the rapid movements of the eyes behind the eyelids that take place during this stage. During REM sleep, the brain patterns most closely resemble those of the awake brain. This is the stage during which dreams occur.
While you’re asleep, your immune system protects you from germs and other invaders that might make you sick. During this time, your body also repairs any damage from the day’s activities.
In addition, a special clear fluid in your brain—called the glymphatic system—removes waste and dead cells from your neurons. This is essential for keeping your brain working properly. Without it, these byproducts can build up to the point where they cause neuronal death. Research has shown that sleep provides the brain with a good opportunity to clear out these debris particles and prevent damage. Insufficient sleep can cause a variety of health problems, including lowered immunity, poor mental performance, and weight gain. The Centers for Disease Control and Prevention recommend that most adults get at least seven hours of sleep each night. If you don’t get enough sleep on a regular basis, it can increase your risk of heart disease, diabetes and other chronic conditions.