Getting enough sleep is essential to our physical and mental health. It helps us function at our best, supports our immune system and prevents illness.
During sleep, our brain and body work at a deep level to repair and strengthen themselves. It is the time when many of our major restorative processes occur, such as tissue growth and protein synthesis.
It also plays an important role in memory formation and learning. It is also essential for maintaining our circadian rhythm and energy levels.
The human body is designed to be asleep for a minimum of eight hours per night, but most people get less than that. Studies show that short sleep duration is associated with increased risk of several chronic diseases, including diabetes and heart disease.
When we are sleeping, our body cycles through four stages of sleep. Three are non-rapid eye movement (NREM) sleep and the last is rapid eye movement (REM). During each of these sleep phases, your thoughts and most body functions slow down.
Each stage of sleep has its own set of physiological characteristics and changes in brain activity, including the amount of neurotransmitters released, the arousal of certain areas of the brain and the release of hormones. Scientists use electroencephalography (EEG) to track these changes over the course of a night.
A person’s sleep cycle begins with light, slow-wave NREM sleep and progresses to deep, restorative REM sleep. During REM sleep, the brain becomes more sensitive to the outside world. This type of sleep is often called dreaming.
Researchers have long suspected that a person’s sleeping habits can impact their overall health and well-being. A study found that people who sleep less than the recommended six or seven hours a night were at increased risk of developing diabetes mellitus.
In addition to contributing to the development of diabetes, short sleep duration is associated with obesity and cardiovascular disease. The body releases hormones during sleep that help repair cells and control the use of energy.
The sleep-wake cycle is influenced by the body’s desire for sleep, called “sleep drive.” A person’s drive for sleep builds up throughout the day, like a hungry pang. When the drive reaches a certain point, the body automatically signals that it is time to go to bed.
During sleep, your body’s glymphatic system, which clears waste from the central nervous system, works more efficiently. This process removes toxins from the brain that build up throughout the day, allowing your neurons to reorganize and function better.
It also gives your body time to recover from illness and reactivate your immune system. If you are sick, your body needs time to rest and repair itself before it can fight off the germs that cause a cold or other respiratory infection.
There are also studies showing that sleep can improve athletic performance, reduce injury risks and increase the efficiency of vaccinations. Research also shows that a lack of sleep can reduce the effectiveness of the flu vaccine, so it’s important to try to get a good night’s sleep when receiving any medical treatment or immunization.