How Sleep Affects Our Health and Well-Being

Sleep is one of the most complex and mysterious body processes known to science. It affects how we work and feel in ways that researchers are only beginning to understand, so it’s no surprise that people who get plenty of rest have lower risk of heart disease, high blood pressure, diabetes and depression. But it’s also no surprise that people who get poor quality or too little sleep struggle with a host of health problems.

For most adults, it takes seven or more hours to get a good night’s sleep. The Centers for Disease Control and Prevention (CDC) recommend this amount of consistent sleep for the average adult. But getting less than that can put you at greater risk for a range of health problems—including heart disease and obesity.

Research shows that when we don’t get enough sleep, our muscles can’t repair themselves, our brains become less capable of learning and retaining memories, and hormones that regulate hunger and stress levels are disrupted. In addition, when we don’t get enough sleep, it can raise our risks for a variety of health problems, including diabetes, obesity, heart disease and depression.

The impact of a bad night’s sleep can last well into the next day and can negatively affect our relationships and work performance. And while the medical community is catching on to the importance of good sleep, many people don’t get the rest they need—particularly Black and Latino people and those with low socioeconomic status, as well as workers who often work overnight or shifts over long periods of time.

There are a number of reasons why people don’t get the sleep they need, including chronic stress and anxiety, difficulty falling asleep or staying awake at night because of mental health issues such as anxiety and depression, and certain medications or substances, including alcohol and caffeine. But the most common cause is a lack of sleep-promoting behaviors, such as going to bed and getting up at regular times each day, maintaining a healthy weight, avoiding excessive exercise, and not smoking.

During a normal night’s sleep, the brain and body cycle through four stages of sleep. Each cycle lasts about 70 to 120 minutes and repeats 4 to 5 times during a 7- to 9-hour sleep period. These cycles include a period of deep sleep, then a period of rapid eye movement (REM) sleep, when we dream.

A growing body of research shows that the key to a good night’s sleep is not just getting to bed and sleeping, but doing so at the same time each day, whether that means sticking to a regular wake-up schedule or taking a daily nap. These are known as “sleep hygiene” habits and are a part of the CDC’s Life’s Simple 7, a set of healthy lifestyle practices that includes sufficient sleep, moderate physical activity, a healthy diet and non-smoking.