What Happens During Sleep?
Getting enough sleep is essential for good health and well-being. It improves your brain function, mood and ability to think and react. It also helps keep your immune system working properly to help you fight off infections and illnesses. Sleep deprivation is associated with many chronic health problems, including heart disease, diabetes and obesity, and it can make you more susceptible to mental illness. The pace of modern life makes it challenging to get a good night’s sleep on a regular basis, and the stresses of everyday living can interfere with normal sleep patterns. But research is shedding new light on the mechanics of sleep and how it contributes to many elements of physical, emotional and mental health.
Researchers have found that sleep is involved in a host of physiological processes, including the control of blood pressure and temperature; regulation of hunger and thirst; muscle tone; memory formation; the release of growth hormone to support tissue repair and growth; the release of neurotransmitters that regulate emotions and feelings; and a variety of other vital processes. It’s no wonder that people who are sleep deprived experience an array of symptoms, from fatigue and irritability to impaired learning and memory, a lack of concentration and difficulty coping with stress, depression and anxiety.
What Happens During Sleep
Within a minute of falling asleep, noticeable changes occur in the body and brain: body temperature falls, breathing and heart rate slow down, and activity in the brain decreases. These changes are triggered by signals from the thalamus and cortex that are regulated by the neurotransmitter GABA. As you enter deeper stages of sleep, the brain activity increases again, and then it shifts to REM (rapid eye movement) sleep, where the eyes move rapidly behind the closed lids and the brain waves are most similar to those of awake people. During REM sleep, the brain is awash in chemicals that are important for memory and emotional processing, and this is the time when dreams usually occur.
The reason you need to go through all these cycles is that sleeping is a vital part of the biological process of restoring homeostasis, the maintenance of a healthy internal environment. Sleep enables the brain to clear away toxins that build up during prolonged wakefulness, such as the amyloid beta protein fragments linked to Alzheimer’s disease.
In addition to regulating our bodies’ energy needs, sleep protects our immune systems and supports the growth and repair of tissues, especially in children and teens. It’s one of the most complex and mysterious activities in the body, and yet it is integral to a person’s mental, emotional and physical health. While there is still a lot to be learned, the growing knowledge of the intricacies of the sleep process is like a partially assembled jigsaw puzzle, with experts identifying some of the pieces and having an idea of what the bigger picture looks like.