An Overview of Sleep and Its Relationship to Health

Sleep is a vital part of human life that contributes to healthy brain function, physical health, and support for growth and development throughout the life span. Over time, getting inadequate amounts of sleep can increase risk for chronic (long-term) health problems and lower quality of life. Researchers are studying all aspects of sleep, from the genes that control when you go to bed to what happens in your brain while you’re sleeping.

Getting enough quality sleep can help prevent cardiovascular disease, high blood pressure, diabetes, obesity, depression, and many other health conditions. Yet, despite the obvious benefits of sleep, millions of Americans don’t get enough sleep to meet recommended guidelines. Why is this, and what does the future hold?

This booklet provides an overview of what we know about sleep and its relationship to health. It also looks at how the amount and quality of sleep varies across the lifespan, why we need sleep, and what happens in the brain during different types of sleep.

Scientists once believed that sleep was a passive activity during which the brain and body were mostly dormant. But that view of sleep changed with the early work done at UChicago by Nathaniel Kleitman, who established the first laboratory dedicated to studying sleep. Kleitman’s all-night electroencephalogram recordings helped him to show that the brain goes through phases of sleep in a predictable pattern over the course of a night.

These patterns are controlled by the circadian rhythms, biological clocks that also regulate aging and other bodily functions. This daily cycle is the basis for our bodies’ drive to sleep and wakefulness, and it helps explain why people are more or less sleepy at different times of day.

The key finding of Rectschaffen’s work was that if mammals are continuously deprived of sleep, they will die within weeks. This ushered in an era of deeper study of sleep and its role in survival.

Research has shown that humans need sleep to maintain the proper balance of hormones, which are key to our health. Sleep can also affect our memories and emotions. It is thought that the brain’s glymphatic system removes waste that builds up during the day and that may be harmful, and that it reorganizes short-term memory into long-term memories during sleep. Sleep is also necessary for regulating emotions and maintaining emotional stability.

A recent large study found that getting adequate sleep is associated with healthier habits, such as a better diet, more physical activity, and lower levels of smoking and alcohol consumption. The study’s authors call for a shift in public health thinking to include adequate sleep as one of the “Life’s Simple 7” factors for heart-healthy living.

The National Institutes of Health recommend that adults get between 7-9 hours of sleep per night, depending on their age. To get the most out of your sleep, try to have a regular routine and avoid using electronics, such as computers and televisions, close to bedtime. You can also try to relax before you go to sleep and keep your bedroom dark, cool, and quiet.