{"id":25425,"date":"2019-06-27T00:00:00","date_gmt":"2019-06-27T00:00:00","guid":{"rendered":"https:\/\/blog-staging.saatva-node-stage.tsc-starts-coding.com\/sleep-stages\/"},"modified":"2025-06-24T11:26:49","modified_gmt":"2025-06-24T15:26:49","slug":"sleep-stages","status":"publish","type":"post","link":"https:\/\/www.saatva-node-stage.tsc-starts-coding.com\/blog\/sleep-stages\/","title":{"rendered":"Here’s What Happens During Each Stage of Sleep"},"content":{"rendered":"\n

You\u2019re probably well aware that sleep is an essential part of overall health<\/a> and well-being. (Just try to make it through a workday on too little shuteye.) <\/p>\n\n\n\n

But how much have you really thought about how it all works and what happens to your mind and body while you\u2019re sleeping (or attempting to snooze)? <\/p>\n\n\n\n

Sometimes, the only way to do a task more successfully is to learn more about how it works. So, to that end: Let\u2019s take a trip back to school and learn about the sleep cycle, what happens during the stages of sleep, and how to get healthier sleep.<\/p>\n\n\n\n

What is the sleep cycle?<\/h2>\n\n\n\n

The sleep cycle is more complicated than you might imagine. It actually consists of five stages of sleep, each of which can last anywhere from about <\/strong>five to 15 minutes. [1] <\/sup><\/p>\n\n\n\n

“Sleep occurs in cycles of about 90 to 110 minutes, with several cycles happening throughout the night,\u201d explains Andres Moran, co-founder and CEO of Complete Sleep<\/a>. \u201cEach cycle consists of two main types of sleep: Non-REM (NREM) and REM sleep<\/a>. <\/p>\n\n\n\n

NREM sleep consists of stages 1 through 4 and accounts for about 75% of adult sleep, while the fifth stage, REM sleep, accounts for 25%. [1] <\/sup><\/p>\n\n\n\n

Fun fact: Babies spend about 50% of their sleep in the REM stage. [2]<\/sup> “Infants spend a significant portion of their sleep time in REM sleep which totals up to 14 hours each day,\u201d says Adrian Pristas<\/a>, MD, medical director of the Center for Sleep Medicine at Hackensack Meridian Health. \u201cAs we age, our sleep requirements decrease. Young adults and teenagers require seven to nine hours of sleep, but adults over 50 need seven to eight hours.” <\/p>\n\n\n\n

Stages of sleep<\/h2>\n\n\n\n

As we mentioned above, there are five distinct stages of sleep\u2014and each one serves a rather specific function. Ahead, let\u2019s explore what happens in each stage of the sleep cycle. <\/p>\n\n\n\n

Stage 1<\/h3>\n\n\n\n

The first stage of sleep is light sleep. During this stage, you drift in and out of sleep, your eyes move slowly, and muscle activity starts to wind down. It\u2019s very easy to be awakened when you\u2019re in the first stage of sleep. [1, 3] <\/sup><\/p>\n\n\n\n

According to Moran, this is the transition between wakefulness and sleep and lasts for as little as a few minutes. <\/p>\n\n\n\n

It’s “characterized by slowing brain waves” and sudden muscle contractions, says Moran\u2014but be aware that you can be easily awakened during this stage. <\/p>\n\n\n\n

This is also when you might experience the feeling of falling, which can cause sudden muscle contractions, a phenomenon known as hypnic myoclonia<\/a>. [4] <\/sup><\/p>\n\n\n\n

If you\u2019re woken up during this sleep stage, you might feel like you haven\u2019t slept at all.<\/p>\n\n\n\n

Stage 2<\/h3>\n\n\n\n

This is when sleep really begins. “Your body temperature drops, heart rate slows, and your brain produces what we call sleep spindles\u2014these are crucial for memory and learning,” says Rafaid Fadul<\/a>, MD, a triple board-certified expert in pulmonary medicine, critical care, and sleep health. [1]<\/sup><\/p>\n\n\n\n

Stages 3 and 4: deep sleep<\/h3>\n\n\n\n

Stages three and four of sleep (known as deep sleep<\/a> or slow-wave sleep) are characterized by slow delta brain waves. [5] <\/sup><\/p>\n\n\n\n

It\u2019s the deepest and most restorative sleep you\u2019ll experience during the night. [1] <\/sup>Deep sleep is crucial for refreshing your mind and body for the next day. <\/p>\n\n\n\n

“Non-REM Stage 3, or deep sleep<\/a>, is when your body does its repair work,” explains Fadul, who says this is when tissues heal, muscles build, and your immune system strengthens. [1]<\/sup> Most of this happens in the first half of the night.<\/p>\n\n\n\n

If you\u2019re woken up during a deep sleep stage, you might feel disoriented for a while\u2014but it might actually be very difficult to be woken up at all at this point in your sleep cycle. [1]<\/sup><\/p>\n\n\n\n

Older adults<\/a> have trouble entering a state of deep sleep\u2014they also tend to sleep less and wake up more often. [6]<\/sup><\/p>\n\n\n\n

It\u2019s also in these stages of sleep that people experience parasomnias (disruptive sleep disorders<\/a>), such as sleepwalking<\/a>. That\u2019s because parasomnias tend to occur when you\u2019re transitioning from non-REM to REM sleep. [1, 7]<\/sup><\/p>\n\n\n\n

Stage 5: REM sleep<\/h3>\n\n\n\n

This sleep stage usually occurs after the first 90 minutes of sleep. [1]<\/sup> The first instance of REM sleep usually lasts around 10 minutes, and each subsequent REM sleep period throughout the night gets longer. [1] <\/sup><\/p>\n\n\n\n

Your final period of REM sleep will last about an hour. During this stage of sleep, your eyes stay closed, but they move super-quickly from side to side. [1]<\/sup><\/p>\n\n\n\n

You also experience increased brain activity at this point in the sleep cycle, which is why dreams most commonly take place in REM sleep. [1] <\/sup>You may dream anywhere from four to six times a night. (Here are common causes of crazy dreams<\/a>.) <\/p>\n\n\n\n

Your body relaxes in REM sleep and your muscles stop moving. “Your brain becomes almost as active as when you\u2019re awake, yet your body is temporarily paralyzed,” says Fadul. <\/p>\n\n\n\n

This paralysis, notes The Better Sleep Council, is a protective measure to stop you from acting out your dreams. [8]<\/sup><\/p>\n\n\n\n

Factors that affect sleep stages<\/h2>\n\n\n\n

Several key factors influence your sleep architecture. According to Fadul, these can include: <\/p>\n\n\n\n