The functions of sleep remain a mystery, but what is known is important: during slumber the body performs essential functions, such as reenergizing cells, cleaning the brain, consolidating memories and regulating hormones. Sleep also plays a crucial role in our mood and can influence everything from appetite to stress levels.
Sleep and health are intimately connected, with research showing that people who regularly get insufficient sleep have a greater risk of developing many common diseases and disorders. Insufficient or poor-quality sleep is also a leading cause of workplace accidents and can contribute to weight gain, heart disease and depression.
Researchers have long been aware of the importance of sleep and have made a number of important discoveries about it. However, there is still much work to be done to further understand the complex relationship between sleep and our health, and to improve the quality of sleep for all.
Sleep is a normal, reversible, recurrent state of reduced responsiveness to external stimuli, characterized by altered brain activity, fluctuations in hormones, and the relaxation of musculature. There are at least four different stages of sleep, ranging from light to deep sleep, and each stage is characterized by specific characteristics such as a decreased ability to be woken up, a slower heart rate, and a lack of muscle movement.
Getting enough sleep each night helps prevent health problems like heart disease, diabetes, depression, and obesity, and may help reduce the risk of high blood pressure and stroke. Insufficient sleep can make it hard to focus, slowing down your mind and making you more likely to forget things. In addition, sleep appears to be important for regulating the body’s immune system and lowering levels of cortisol, which is a stress hormone.
Some people think that skipping sleep is a sign of strength and determination, but missing out on the recommended amount of sleep each night can be harmful to your health. In fact, sleep deficiency has been linked to a wide range of medical and mental health conditions, including heart disease, diabetes, high blood pressure, anxiety, depression, and poor concentration and memory.
During a night of sleep, the body goes through three to five sleep cycles, with each cycle consisting of four stages of sleep. The first three stages are non-rapid eye movement (NREM) sleep, and the fourth is REM sleep, when dreams occur. REM sleep occurs in cycles that take about 90 minutes to two hours.
Scientists have established the need for a new emphasis on sleep in education, clinical practice, inpatient and long-term care, public health promotion, and the workplace. This is reflected in the inclusion of sleep objectives in Healthy People 2030 and its predecessor, Healthy People 2020.