We all know that sleep is important, and most of us probably aspire to get more of it each night. But how much sleep does the average person really need to maintain health? Do we actually need eight hours a night, or is seven hours of sleep just enough?
The amount of sleep we need changes over time from childhood through adulthood, and individual sleep needs can also vary based on several factors. However, experts generally recommend a certain target range for each age group. For adults, it's seven to nine hours. So what if you're on the bottom cusp?
Experts discuss how much sleep people actually need, whether sleeping seven hours a night is enough, and how to get more sleep if you aren't feeling rested.
Is 7 hours of sleep enough?
Yes, seven hours of sleep is generally enough for most healthy adults. People who regularly sleep seven hours a night can feel rested and maintain good health.
In a joint consensus published by the American Academy of Sleep Medicine and the Sleep Research Society, experts recommend seven hours — not eight — as the "magic number" for most healthy adults.
“When we talk about ideal number of hours of sleep, it's actually a range,” Shelby Harris, Psy.D., a clinical psychologist specializing in behavioral sleep medicine and director of sleep health at Sleepopolis, tells TODAY.com. About 70% of adults need between seven and nine hours a night, says Harris.
However, sleeping seven hours a night may not be enough for some people depending on their baseline sleep needs and health. How do you figure out your individual sleep needs?
The amount of sleep a person needs is roughly the number of hours they would sleep naturally — without any external disruptions or alarms — to feel fully rested the next day, Dr. Bhanu Kolla, a sleep physician and psychiatrist at the Mayo Clinic, tells TODAY.com.
The distribution of sleep needs in a population is shaped like a bell curve, Kolla notes. The vast majority of people fall in the middle, between seven and nine hours, but there are also people on either side of the curve and extreme outliers. Some people may only need six hours of sleep to function, whereas others need more than nine.
Generally, if you wake up feeling refreshed, you don’t feel sleepy throughout the day, you fall asleep easily and wake up around the same time, you’re probably getting enough sleep, the experts say. If that doesn’t happen when you sleep seven hours, you may need more.
In addition to sleep duration, sleep quality and timing are also important, says Harris. Sleep quality can be affected by snoring, sleep apnea, insomnia, stress and other health issues, she adds.
Possible signs of poor sleep quality include waking up repeatedly throughout the night, not feeling rested after getting seven to nine hours of sleep, or experiencing nighttime breathing difficulties, per the U.S. Centers for Disease Control and Prevention.
Health impacts of only sleeping 7 hours
Sleeping seven hours a night won't have any negative health consequences for most healthy people, experts say. However, only setting aside seven hours for bed doesn't leave much wiggle room if you have trouble falling asleep, wake up during the night or have poor sleep quality.
It’s also common for people to need more sleep than they normally do when they are sick, Kolla notes. Seven hours may not be enough for someone who is fighting off an infection, and they may need to sleep for longer until they recover.
It’s important to get plenty of it when recovering from illnesses such as the common cold or flu.
Consequences of sleep deprivation
“Sleep is the bedrock from which everything else is built, so it impacts almost every part of your body,” says Harris.
If you consistently get less sleep than your body needs, this can lead to chronic sleep deprivation, which has short- and long-term health consequences. Even one night of too little sleep can take a toll.
People who are chronically sleep deprived may not realize how tired they are because the constant tiredness and other symptoms have become a norm. “Studies have shown that people don’t perceive themselves to be as sleepy over time, even though they’re getting less sleep than they require,” says Kolla. However, the body is still racking up sleep debt, which has a host of health consequences.
Drowsiness and mood changes
The following day after getting too little sleep for your body, you may feel excessively drowsy or feel the need to sleep throughout the day. You may feel like you can doze off during everyday activities such as watching television, sitting in an office or classroom, or after eating, per the National Institutes of Health.
Losing sleep can also cause heightened irritability or moodiness the next day, says Kolla. Sleep deprivation may also cause a person to feel more sad or lack motivation, per the National Institutes of Health.
Cognitive impairment
Not getting enough sleep can seriously impair cognitive ability and executive functioning, leading to slower reaction times and poorer working memory or performance, Dr. Andrew Varga, a neuroscientist and physician at the Mount Sinai Integrative Sleep Center, tells TODAY.com.
The acute effects of sleep deprivation can mimic those from alcohol. "You might not notice, but your concentration and coordination is going to be off," says Harris, adding that the risk of accidents and falls increases when you're sleep deprived.
Chronic health conditions
In the long-term, sleep deprivation is associated with a higher incidence of high blood pressure, heart attack, stroke, heart disease, Type 2 diabetes, and kidney disease.
Sleep deprivation is also associated with increased inflammation, which increases the risk of a number of chronic diseases.
Immune function
Sleep is crucial for immune function, TODAY.com previously reported. Not getting enough sleep can not make it harder for the body to fight off infections. Research shows that people who don't sleep enough may also be more susceptible to getting sick after being exposed to a virus, per the Mayo Clinic.
Mental health problems
Consistently sleeping too little is also linked to an increased risk of depression, anxiety, bipolar disorder, and Alzheimer's, says Kolla. "The longer you go getting less sleep, the greater risk," Kolla adds.
How much sleep do you need?
The AASM recommends each age group get the following amount of sleep on a regular basis:
- Infants (4 to 12 months) should sleep 12 to 16 hours per 24 hours
- Children (1 to 2 years) should sleep 11 to 14 hours per 24 hours
- Children (3 to 5 years) should sleep 10 to 13 hours per 24 hours
- Children (6 to 12 years) should sleep 9 to 12 hours per 24 hours
- Teenagers (13 to 18 years) should sleep 8 to 10 hours per 24 hours
- Adults should sleep 7 or more hours per night
The eight-hours-a-night rule for adults is a bit of a myth, says Harris. “It’s not actually that everyone needs eight hours. It’s that most people need between seven and nine. ... That’s where it comes from,” she adds.
Individual sleep needs are influenced by genetic, medical, behavioral and environmental factors, according to AASM. “Sleep duration is like shoe size. Everyone has varying sizes, but they range around the same area, with some outliers,” says Harris.
Some adults need nine or 10 hours of sleep every night to feel rested, says Harris, whereas others may find they only need seven, and sleeping more isn’t necessarily better. “The more you try to force yourself to get eight if you’re not an eight-hour-sleeper, the worse it’s going to be,” says Harris.
A tiny subset of people are considered natural “short-sleepers” because they can routinely sleep six hours a night or less and function normally without needing to catch up, Varga says, adding that short-sleepers are born with a rare inherited gene mutation.
But many people who only sleep five hours a night are not doing so because it's what their body needs. Rather, it's because they restrict themselves or aren’t able to sleep longer, the experts note.
Work schedules, social obligations, poor sleep hygiene and sleep disorders are common reasons people don’t get the recommended amount of sleep, says Harris.
How to get more sleep
"Make sleep a priority," says Harris. Between life's responsibilities and distractions, there are plenty of reasons why it can be hard to prioritize sleep, but the experts recommend the following steps:
- Maintain a consistent sleep schedule
- Create a comfortable, quiet, dark sleeping environment
- Avoid screens for at least 30 minutes to one hour before bedtime
- Get regular exercise
- Limit caffeine and alcohol intake
- Avoid napping for too long or too close to bedtime, especially if you have trouble falling asleep
If you still find yourself struggling to get enough sleep or you have concerns about your sleeping habits, talk to your doctor or a sleep specialist, the experts emphasize.
