December 3, 2021

Sleep: How Much You Need and Its 4 Stages

When you sleep, your body rests, recovers and rebuilds itself through four stages

A person counts sheep as they try to fall asleep.

There’s a reason we tell our loved ones to get a good night’s sleep. For many of us, the benefits of a good night’s rest are second nature, as we tend to feel better about ourselves and more competent to take on responsibility when we’re well rested. But for many others, we struggle with getting just the right amount of sleep. According to the National Sleep Foundation, about half of all Americans feel sleepy from three to seven days a week — a sure sign that we could all use a little more.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

How much sleep do you need?

The younger you are, the more sleep you need. Babies need a lot of sleep. As kids grow, their sleep needs decrease. “By adulthood, most healthy people need 7 to 8.5 hours,” says psychologist and sleep disorder specialist Michelle Drerup, PsyD, DBSM. Here’s how much kids and adults need, on average according to the Centers for Disease Control and Prevention:

Age
0-3 months
Hours of sleep needed
14-17
4-12 months
Hours of sleep needed
12-16
1-2 years
Hours of sleep needed
11-14
3-5 years
Hours of sleep needed
10-13
6-12 years
Hours of sleep needed
9-12
13-18 years
Hours of sleep needed
8-10
19-64 years
Hours of sleep needed
7-9
65+ years
Hours of sleep needed
7-8

Though sleep needs vary depending on your genetics, most adults fall in the seven-to-nine-hour range. If you think you thrive on less, you may want to reconsider.

“There are people who are short sleepers, but it’s pretty rare,” Dr. Drerup notes. “We’re not very good judges of how sleep loss affects us, and most people who think they do well on little sleep would probably function better with a little more.”

One common misconception is that older adults don’t need as much sleep as they did in middle age. Older adults should still aim for at least seven hours, Drerup says.

“Older adults have different sleep patterns. They tend to sleep more lightly and may wake earlier in the morning,” she says. “But you still need the same amount of sleep over 24 hours, so if you’re sleeping less at night, you might need a nap during the day.”

Benefits of sleep

Sleep is a catch-all that benefits your physical, mental and emotional health. When you’re sleeping, your body has the chance to rest and recover — and these restorative properties even occur on a cellular level. Some major benefits of sleep include:

Advertisement

Of course, developing consistent sleeping patterns to maximize these benefits can be a battle all on its own. Dr. Drerup offers these tips for getting the most out of your sleep schedule:

  • Wind down: Before bedtime, wind down by turning off electronic devices (aim for an hour beforehand), turning down lights and doing calming activities (like taking a warm bath, reading and relaxation) that will help your body get sleepy.
  • Go slow: If you’re used to staying up until 2 a.m., you aren’t likely to fall asleep at 11 p.m. Start by shifting your bedtime back by 15 or 20 minutes. After a couple of days, turn it back another 20.
  • Be consistent: If you cut sleep short during the week, you won’t be able to fully make up that sleep debt on weekends. Instead, aim to go to bed and wake up close to the same time each day.
  • Be flexible: “You won’t be perfectly consistent every night,” she says. “But if you’re within an hour of your ideal sleep target, that’s a good goal.”

Symptoms and side effects of sleep deprivation

Even losing out on one or two hours of sleep can impact your mood and overall health. So how do you know if you’re not getting enough sleep or if your grogginess from the night before is a one-time fluke? Here are some common signs and symptoms of sleep deprivation you should look out for:

  • Struggling to stay awake when inactive (like when watching TV).
  • Difficulty concentrating.
  • Forgetfulness.
  • Slowness in responding to others.
  • Loss of motivation.
  • Increase in moodiness or temper.
  • Yawning constantly.
  • Day-long periods of drowsiness.
  • Needing multiple power naps (sleeping in short periods).
  • You’re tired all the time.

It’s important to keep an eye on these symptoms, especially if they occur daily or weekly, as shortchanging your sleep long-term can lead to a host of long-term problems, including:

Stages of sleep

An average sleep cycle lasts about 90 minutes. Ideally, you need four to six cycles of sleep every 24 hours to feel fresh and rested. Each cycle contains four individual stages: three that form non-rapid eye movement (NREM) sleep and one rapid eye movement (REM) sleep. While the time spent in each stage varies the longer you’re asleep, and you might bounce between stages each night, each individual stage remains largely the same.

NREM Stage One

This stage of light sleeping lasts five to 10 minutes. During this stage you’re “dozing off,” as your body and brain activity begins to slow down. If you’re woken during this stage, you may feel as if you haven’t fallen asleep at all.

NREM Stage Two

During this stage of light sleeping, your muscles begin to relax as your body temperature drops and your heart rate and breathing slow down. During this stage, your eye movement stops and your brain waves slow. There are occasional bursts of brain waves called sleep spindles that are believed to assist with storing your memories and shutting down your senses so your sleep won’t be interrupted. This stage prepares you to enter into deep sleep and may last up to 25 minutes.

Advertisement

NREM Stage Three

This stage is known as deep sleep, in which your eyes and muscles are fully at rest. During this stage, your body is repairing itself by regrowing tissue, strengthening your immune system and building bones and muscle. It is increasingly difficult to wake you up during this stage, and if you are woken, you may experience a period of disorientation and brain fog for up to 30 minutes or an hour. During earlier sleep cycles, this stage could last 20 to 40 minutes and gets increasingly shorter as sleep cycles progress. As you get older, you spend less time in this stage and more time in Stage Two.

REM Sleep

You dream during this stage. Your brain activity greatly increases and can even match or exceed your usual brain activity when you are awake. Your muscles enter a state of temporary paralysis, except for your eyes (which move rapidly during this stage) and the muscles you need to breathe. Your breathing gets faster, and your heart rate and blood pressure increase. Usually, the first period of REM sleep occurs around 90 minutes into your sleep cycle and lasts about 10 minutes. Each of your later REM stages gets longer the more hours you remain asleep.

Trouble sleeping? When to see a doctor

About 70 million people in the U.S. experience sleep disorders, ranging from insomnia to sleep apnea, restless legs syndrome, narcolepsy and more. If you’re concerned about your sleep patterns or if you’re experiencing some of these disorders, schedule an appointment with your family doctor or a sleep clinic, as you may need to participate in a sleep study.

Related Articles

Female swimmer in the water at edge of a pool
December 1, 2023
Can Exercise Reduce Your Risk of Breast Cancer?

Physical activity and weight management can minimize your chances of getting the disease

Two people standing in the cold.
November 29, 2023
10 Colds Not To Catch This Winter

The flu, RSV, COVID-19, pneumonia and more typically circulate during cold weather months

Parent breastfeeding baby on bed, against the headboard.
November 27, 2023
Looking for Foods To Increase Your Milk Supply? Think Big Picture

No single food will increase your milk, but an overall healthy diet will help

Parent uses manual baby aspirator to open up nasal passages of baby.
November 22, 2023
Prevent Phlegm in Your Baby’s Throat With a Nasal Aspirator

Keeping your baby’s airways clear of mucus helps with breathing and feeding

Two different vaccines and needles displayed in foreground.
November 22, 2023
Which Vaccines Can You Get at the Same Time?

Getting routine vaccinations together can save you time and may be more effective

Muffins and sweetbreads with frosting on trays at bakery.
November 22, 2023
13 Foods That You Didn’t Know Contain Dairy

Be sure to check the labels of common foods like canned tuna, bread, hot dogs and chocolate

Toddler drinking from a cup while at the table during dinner.
November 21, 2023
Toddler Drinks — What Does the Research Say About These Products?

They aren’t unhealthy, but they’re probably a waste of money

person drinking coffee at computer at night
November 15, 2023
Is It Bad To Drink Coffee Late at Night?

Depending on your sensitivity to caffeine, a late-night cup may be just fine

Trending Topics

group of hands holding different beverages
November 14, 2023
10 Myths About Drinking Alcohol You Should Stop Repeating

Coffee won’t cure a hangover and you definitely shouldn’t mix your cocktail with an energy drink

Person applies moisturizer as part of their skin care routine after a shower.
November 10, 2023
Korean Skin Care Routines: What You Need To Know

Focus on the philosophy — replenishing and respecting your skin — not necessarily the steps

glass of cherry juice with cherries on table
November 8, 2023
Sleepy Girl Mocktail: What’s in It and Does It Really Make You Sleep Better?

This social media sleep hack with tart cherry juice and magnesium could be worth a try

Ad