How Much Sleep You Need, According to Experts
Here's what can happen when you're sleep deprived.
Sleep is essential for optimal safety, mood, performance, and health. As one of the three pillars of a healthy lifestyle (the other two being diet and exercise), the amount of sleep you get can dramatically improve or hinder your quality of life in various ways.
How many hours of sleep do you need?
The amount of sleep a person needs each day varies with age, according to the National Sleep Foundation.
- Newborns (0-3 months) need 14-17 hours
- Infants (4-11 months) need 12-15 hours
- Toddlers (1-2 years) need 11-14 hours
- Preschoolers (3-5) need 10-13 hours
- Children (6-13) need 9-11 hours
- Teenagers (14-17) need 8-10 hours
- Adults (18-64) need 7-9 hours
- Older adults (65+) need 7-8 hours
Pregnancy, sleep deprivation, and poor sleep quality can also affect how much sleep you need, according to the Mayo Clinic.
Who’s at risk of sleep deprivation?
In short, almost everyone is at risk of catching fewer zzz’s than they really need. Whether you’re a shift worker who sleeps at odd or varying hours, a new parent attending to a waking baby, or someone who is ill or stressed, you’re bound to experience periods when you log fewer hours of sleep than you need.
Children, and especially adolescents, who often keep late hours during the school week, are particularly vulnerable. According to research presented at the American Academy of Pediatrics 2019 national conference, fewer than half of all 6- to 17-year-olds are getting 9 hours of sleep on most nights.
Why do older adults sleep less?
Older adults need about that same amount of slumber as other adults, but they tend to sleep more lightly and for shorter time spans than younger adults.
They have less “deep slow-wave sleep”—the most restorative stage of sleep—“and their sleep is more fragmented, meaning that they're going to wake up more frequently,” Kenneth P. Wright Jr., PhD, assistant professor of integrative physiology and director of the Sleep and Chronobiology Lab at the University of Colorado at Boulder, tells Health.
“And when they do wake up,” adds Wright, “they tend to be awake for a longer period of time than young adults.”
To put it simply, older adults’ sleep difficulties are often related to the natural aging process, explains Wright. He says another reason could be that many sleep disorders increase with age.
What health risks are associated with sleep deprivation?
Inadequate sleep negatively affects health in a number of ways, says the American Academy of Sleep Medicine.
Sleep deprivation can really do a number on your mood and performance. It can make you feel irritable, anxious, or depressed. It can make it difficult to concentrate on everyday tasks. Lack of sleep can become a safety hazard when it results in drowsy driving and workplace injuries, says the sleep organization.
Digestive problems are very common in individuals who have poor sleep quality and probably account for the most common reason why people miss work, Christopher Winter, MD, owner of Charlottesville Neurology and Sleep Medicine in Virginia and medical director of the Martha Jefferson Hospital Sleep Medicine Center, tells Health.
“Cancer is another disorder that's been linked to poor quality sleep,” notes Dr. Winter. “Individuals who work unusual schedules and have unpredictable sleep timing over time may show an increased risk for certain types of cancers, particularly women and breast cancer.”
Sometimes sleep deprivation is a consequence of a sleep disorder. People with sleep apnea experience brief and repeated pauses in breathing during sleep, making it difficult to slumber soundly. Research suggests those who suffer from this sleep disorder are more likely to experience irregular heartbeats, heart failure, heart attacks, and strokes.
Regular lack of sleep can make symptoms of an existing chronic condition seem worse and may even increase the risk of developing certain conditions—high blood pressure, obesity, diabetes, and heart attack, to name a few. It becomes a vicious cycle. People end up reaching for medicines to treat their symptoms ms, which only worsens the quality of their sleep, says Dr. Winter. And that, in turn, can negatively impact existing medical conditions.
He explains that individuals who are not getting enough sleep also are more susceptible to illnesses, as poor quality sleep weakens the immune system.
“It’s pretty difficult to figure out systems within the body that are not affected,” observes Dr. Winter.
How do you build good sleeping habits?
Consistency is important. Dr. Winter recommends trying to build in a little bit more consistency and not having such a wide span of sleep timing.
He also recommends going to bed and waking up around the same time every day. “If you have the opportunity to sleep in until two in the afternoon on the weekend that might not be the smartest thing to do from a sleep perspective,” says Dr. Winter.
Sleep Education recommends limiting exposure to bright light in the evening, turning off electronic devices at least 30 minutes before bedtime, not eating a large meal before bedtime, avoiding consuming caffeine or alcohol before bedtime, and reducing your fluid intake before bedtime.
Issues related to healthy sleep
In our current culture, someone who falls asleep immediately is viewed as a good sleeper. In reality, it’s quite the opposite.
“I'm much more concerned about the patient who can fall asleep in any situation than I am an individual who might take 30 or 45 minutes to fall asleep every now and then,” says Dr. Winter. The reason? People who can fall asleep quickly at any time and anywhere may have narcolepsy, a chronic sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks.
That said, people who consistently have difficulty falling asleep may have insomnia. Some other common symptoms of this sleep disorder include frequent waking during the night and having trouble going back to sleep, waking up too early in the morning, not feeling well-rested after a night’s sleep, and problems with concentration, according to the Cleveland Clinic.
This, among other reasons, is why many sleep disorders go unrecognized and untreated in clinical practice. Historically, doctors didn't get much training on recognizing sleep disorders. In recent years, there's been a push to bring doctors up to speed on the potential health risks of sleep disorders, and so now more people with sleep disorders are being properly diagnosed and treated, says Wright.
If you think you have a sleep issue, voice your concerns to your doctor, says Dr. Winter. “Sleep disorders are often difficult to diagnose because patients don't talk about sleep with their doctors, and doctors are not great about asking patients about their sleep.”
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