What Are the Stages of Sleep and How Much Do You Need

Getting enough good quality sleep is a cornerstone of good health. According to the U.S Department of Health and Human Services (HHS), sleeping well helps you:

Get sick less often
Maintain a healthy body weight
Reduce your risk of diabetes and heart disease
Lower stress
Think clearly and make better decisions
Get along with others

Here’s how much sleep you need for optimal health

“The amount of time you need to sleep varies based on your age,” said Salma Patel, MD, a sleep medicine specialist at Banner – University Medical Center Tucson. It’s no surprise that babies need more sleep than older children and adults.

Here’s how much sleep you should be getting in 24 hours, including naps:

4 to 12 months old: 12 to 16 hours
1 to 2 years old: 11 to 14 hours
3 to 5 years old: 10 to 13 hours
6 to 12 years old: 9 to 12 hours
13 to 18 years old: 8 to 10 hours
Adults: 7 to 8 hours

“Sleep needs can vary,” Dr. Patel said. “You should focus more on whether you feel refreshed when you wake up and how well you function in the daytime rather than the total number of hours you’ve slept.”

The effects of poor sleep habits

Although sleep needs may be different for each person, as an adult, sleeping fewer than four hours or more than nine hours can increase the chances of death from coronary artery disease (CAD), cancer and stroke. Poor sleep habits are also associated with heart arrhythmias and increased chances of developing CAD and hypertension.

If you don’t get enough sleep, you could also suffer from decreased performance, attention, concentration and increased reaction time. Sleep deprivation is the most common cause of excessive daytime sleepiness (EDS).

On the other hand, getting too much sleep can also be a problem. Excessive sleep may result in exhaustion and irritability because long sleepers tend to spend less time in deep sleep compared to short sleepers.

What are the stages of sleep?

As you sleep, you cycle through four stages of sleep that are important for your health:

NREM 1: In this stage, you doze off or transition from being awake to being asleep. You might still be aware of your surroundings and wake up easily. If you wake, you may feel as though you were not sleeping. However, you may dream.
NREM 2: As you move into this stage, your muscles relax, you breathe more slowly and your heart rate slows down. Your eyes stop moving. In healthy sleep, you will spend about half of your sleeping time in this stage.
NREM 3: This stage is also called delta or slow-wave sleep, named after the brain waves that occur at this time. In this deep sleep stage, your body rests, restores and repairs itself. It’s hard to wake up during this stage of sleep, and if you do awaken, you may feel disoriented. Early in the night, this stage lasts about 45 to 90 minutes (about one and a half hours), and it gets shorter as the night goes on. This stage decreases as you get older and may disappear in older adults.
REM: In rapid eye movement (REM) sleep, your brain is active, and your eyes move around. Your breathing, heart rate and blood pressure increase. This stage is when you dream, and you may remember these dreams. The REM stage gets longer later in the night.

How can you tell if you’re getting enough sleep?

If you feel tired and sleepy the next day, you probably aren’t sleeping enough or sleeping well. There are a few steps you can take to help you sleep better:

Maintain a consistent bedtime and wake time, even on weekends
Keep your bedroom dark, quiet and comfortable and avoid using your computer, cell phone or TV in the bedroom
Avoid exercising within three hours of bedtime or consider exercising in the morning rather than in the evening
Manage any stress, anxiety or pain
Avoid alcohol, tobacco, caffeine and heavy meals close to bedtime
Control any medical symptoms keeping you up, such as those that stem from heartburn and asthma

If you try these steps and your sleep doesn’t improve, talk to your doctor or a sleep specialist. You may have a sleep disorder. For example, if you have sleep apnea, you may feel tired even though you think you’ve slept long enough. That’s because sleep apnea is preventing you from getting enough slow wave and REM sleep. Treatment can help.

It’s also important to note that some heart conditions can cause poor sleep. Patients with congestive heart failure may suffer from a form of sleep apnea called central sleep apnea (CSA), and people with CAD may have their sleep disrupted by angina.

The bottom line

In good quality sleep, as you cycle through the four sleep stages, your body restores and repairs itself. The younger you are, the more sleep you need. If you would like to connect with a sleep specialist who can help you improve your sleep or treat any sleep problems you may have, reach out to Banner Health.

Have you listened?

Your Guide to the Amount and Stages of Sleep You Need