When thinking about getting the sleep you need, it's normal to focus on how many hours you're sleeping. While sleep duration is certainly important, it's not the only part of the equation.
It's also important to think about sleep quality and whether sleep time is really restorative. Progressing smoothly through the sleep cycle, which consists of four separate sleep stages, is an essential part of quality rest.
Each stage of sleep plays a role in waking up refreshed in mind and body. Understanding the sleep cycle also helps explain how certain sleep disorders, including insomnia and obstructive sleep apnea, can affect a person's sleep and health.
What is the sleep cycle?
The dream is not uniform. Instead, your total sleep through the night is made up of several rounds of the sleep cycle, which is made up of four distinct phases. On a typical night, a person appears four to six sleep cycles trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference . Not all sleep cycles are the same length, but on average, each one lasts about 90 minutes.
Are all sleep cycles the same?
is normal for changing sleep cycles trusted source National Institute of Neurological Disorders and Stroke (NINDS) NINDS aims to gain fundamental knowledge about the brain and nervous system and use that knowledge to reduce the burden of neurological disease. See full reference as you go through your nocturnal slumber. The first sleep cycle is usually the shortest, lasting between 70 and 100 minutes, while subsequent cycles are typically between 90 and 120 minutes. The composition of each cycle, how much time is spent in each sleep stage, also changes throughout the night.
Sleep cycles can vary from person to person and from night to night based on a variety of factors including age, current sleep patterns and alcohol consumption.
What are the stages of sleep in a normal sleep cycle?
There are four stages of sleep, including one forI am REM (Rapid Eye Movement).and three that make up non-REM sleep (NREM). These phases are determined based on the analysis of brain activity during sleep, which reveals distinct patterns that characterize each phase.
| phases do they are | kind of am | other names | normal length |
|---|---|---|---|
| Level 1 | NREM | N1 | 1-7 minutes |
| Level 2 | NREM | N2 | 10-25 minutes |
| level 3 | NREM | N3, I'm de ondas lentas (SWS), I'm delta, I'm deep | 20-40 minutes |
| Level 4 | fast eye movement | REM sleep | 10-60 minutes |
The division of a person's sleep into different cycles and phases is commonly called sleep architecture. When someone undergoes a sleep study, their sleep architecture can be visualized on a hypnogram or diagram.
NREM sleep patterns
NREM sleep consists of three different phases. The higher the level ofNREM sleep, the more difficult it is to wake a person.
Level 1
Stage 1, also called N1, is essentially when a person falls asleep for the first time. This phase usually lasts from one to seven minutes.
During N1 sleep, the body has not fully relaxed, although body and brain activity slows down during short periods of movement. There are small changes in brain activity associated with falling asleep during this phase.
It is easy to wake someone in this stage of sleep, but if undisturbed, it can quickly move into Stage 2. As the night progresses, a regular sleeper may not spend much more time in Stage 1 as it progresses. sleep cycles
Level 2
During stage 2 or N2, the body enters a more subdued state that includes a drop in temperature, relaxed muscles, and slower breathing and heart rate. At the same time, the brain waves show a new pattern and eye movement stops. In general, brain activity slows down, but there it is short bursts of activity trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference They really help to resist awakening from external stimuli.
Stage 2 sleep can last anywhere from 10 to 25 minutes during the first sleep cycle, and each stage N2 can last all night. Overall, a person typically spends about half of their sleep time in N2 sleep.
level 3
Stage 3 sleep is also known as N3 or deep sleep and it's harder to wake someone up when they're in this stage. Muscle tone, pulse rate, and breathing rate all decrease in N3 sleep as the body continues to relax.
Brain activity during this period exhibits an identifiable pattern of what are known as delta waves. For this reason, stage 3 can also be called delta sleep or slow wave sleep (SWS).
Experts believe this phase is essential for restful sleep, allowing the body to repair and grow. It can also support the immune system and other important bodily processes. Although brain activity is reduced, there is evidence that deep sleep contributes insightful thinking trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference , creativity trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference and memory.
During the first half of the night, you spend most of your time in deep sleep. During the first few sleep cycles, N3 phases usually last from 20 to 40 minutes. As you continue to sleep, these periods shorten and you spend more time in REM sleep.
REM sleep patterns: what is REM sleep?
During REM sleep, brain activity increases and approaches levels seen during wakefulness. At the same time, the body experiences atony, which is a temporary paralysis of the muscles, with two exceptions: the eyes and the muscles that control breathing. Although the eyes are closed, you can see that they are moving quickly, hence the name of this stage.
REM sleep is believed to be essential for cognitive functions such as memory trusted source updated More than 2 million healthcare professionals worldwide choose UpToDate to help them make the right care decisions and achieve better health outcomes. UpToDate provides evidence-based clinical decision support that is clear, actionable, and rich in real-world insights. See full reference , Learning & creativity trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference . REM sleep is known for the most vivid dreams, which is explained by the significant increase in brain activity. Dreams can occur at any stage of sleep, but are less frequent and intense during NREM periods.
Under normal circumstances, you don't enter REM sleep until you've slept for about 90 minutes. During the night, REM phases become longer, especially in the second half of the night. While the first REM phase can only last for a few minutes, the later phases can last about an hour. Overall, REM stages make up about 25% of sleep in adults.
Why are sleep stages important?
The stages of sleep are important because they allow the brain and body to rest and develop. I don't get tired of either one.I'm deepjREM sleepmay explain some of the profound consequences of insufficient sleep Think trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference , emotions and physical health. Sleepers who wake up frequently in the early stages, such as B. people withsleep apnea, you may have trouble properly transitioning into these deeper stages of sleep. people withinsomniaI may not make itI am complete enoughto accumulate the necessary time in each step.
What affects sleep stages?
While there is a typical pattern to sleep stages, there can be significant individual variation based on a set of factors trusted source National Library of Medicine, information on biotechnology The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See full reference .
- Years:The time in each stage changes dramatically throughout a person's life.newbornThey spend much more time in REM sleep and can enter the REM phase as soon as they fall asleep. As they age, their sleep resembles that of adults. Older adults tend to spend less time in REM sleep.
- Current sleep patterns:When a person sleeps irregularly or insufficiently for a period of days or longer, it can lead to an abnormal sleep cycle.
- Alcohol:Alcohol and some other drugs can alter sleep architecture. For example,AlcoholREM sleep declines in the early evening, but as the alcohol wears off, there is a rebound in REM sleep with prolonged REM periods.
- Sleep disorders:Sleep apnea, restless legs syndrome (RLS) and other conditions that cause multiple awakenings can interrupt a healthy sleep cycle.
How can you have a healthier sleep cycle?
While you can't fully control your sleep cycle, there are steps you can take to improve your chances of making healthy progress through each sleep stage.
An important step is to focus on improving yourhygiene I am, which relates to your sleep environment and sleep-related habits. A more consistent sleep pattern, natural light, avoiding alcohol before bed, and eliminating noise and light interruptions can help you sleep without interruptions and promote proper alignment of your circadian rhythm. Yourmattress,cushion, jsheetsit can also contribute to the comfort of your sleeping environment.
When you find out you haveexcessive daytime sleepinessor suspect that you suffer from a sleep disorder such as sleep apnea, it is important to talk to a doctor who will be able to guide your treatment in the most appropriate way. Addressing the underlying issues can pave the way for fuller, more restful sleep cycles.