The Importance of Sleep

As you close your eyes and drift into a deep sleep, notable changes take place in the brain and body. Within minutes, your body temperature drops, eye movement ceases and brain activity slows. Then, in stage two of sleep, your breathing and heart rate slow down, as does muscle activity.

During this period, the brain releases proteins that help repair the damage done to your body and brain during the day. It also clears out waste and supports your immune system, and it helps consolidate memories. But sleep does more than just make you feel rested — it’s crucial to physical health and mental well-being throughout your life. A growing body of research demonstrates that getting adequate sleep is associated with good judgment, problem solving and other cognitive functions. And a lack of sleep is tied to a variety of health problems, including obesity and type 2 diabetes, heart disease, depression and memory loss.

Scientists aren’t sure why we sleep, but it seems to be a basic human need fine-tuned over millions of years of evolution to enable almost all the body’s functions. “It’s a very complex and highly active process that is important to our quality of life,” says neurologist Mark Wu, M.D., a Johns Hopkins sleep expert.

Most people need seven to eight hours of sleep each night. But everyone’s needs vary, and it’s best to listen to your own body and adjust your sleeping habits accordingly. Children and teenagers need more sleep than adults, primarily to facilitate growth and development. And older adults need a little less sleep.

Getting sufficient sleep can help you maintain a healthy weight, manage stress, avoid accidents, and perform better at work and in sports. But poor sleep is linked to a host of other health issues, including high blood pressure, heart disease and stroke, type 2 diabetes, depression, and dementia.

Many of the things that happen during sleep aren’t fully understood, but scientists are making progress. They know that sleep is linked to a number of hormones and the production of cerebrospinal fluid, or CSF, which plays a role in your memory. They also know that CSF contains amyloid-beta, a protein that’s been linked to Alzheimer’s and other brain disorders.

In addition to following a healthy bedtime routine, you can improve your sleep by staying away from caffeine and other stimulants at least a few hours before bed, using a dark, cool, quiet room for your bedroom, and exercising during the day. You can also talk to your doctor if you’re having trouble sleeping or are worried about your sleeping patterns. They may recommend a test or treatment.