How Much Sleep Do We Really Need?
Humans, like all animals, need sleep, along with food, water and oxygen, to survive. For humans sleep is a vital indicator of overall health and well-being. We spend up to one-third of our lives asleep, and the overall state of our “sleep health ” remains an essential question throughout our lifespan.
Most of us know that getting a good night’s sleep is important, but too few of us actually make those eight or so hours between the sheets a priority. For many of us with sleep debt , we’ve forgotten what “being really, truly rested” feels like.
To further complicate matters, stimulants like coffee and energy drinks, alarm clocks, and external lights—including those from electronic devices—interferes with our “circadian rhythm ” or natural sleep/wake cycle.
Sleep needs vary across ages and are especially impacted by lifestyle and health. To determine how much sleep you need, it's important to assess not only where you fall on the "sleep needs spectrum," but also to examine what lifestyle factors are affecting the quality and quantity of your sleep such as work schedules and stress.
Why Is Sleep Important?
Sleep plays a vital role in good health and well-being throughout your life. Getting enough quality sleep at the right times can help protect your mental health, physical health, quality of life, and safety.
The way you feel while you're awake depends in part on what happens while you're sleeping. During sleep, your body is working to support healthy brain function and maintain your physical health. In children and teens, sleep also helps support growth and development.
The damage from sleep deficiency can occur in an instant (such as a car crash), or it can harm you over time. For example, ongoing sleep deficiency can raise your risk for some chronic health problems. It also can affect how well you think, react, work, learn, and get along with others.
Healthy Brain Function and Emotional Well-Being
Sleep helps your brain work properly. While you're sleeping, your brain is preparing for the next day. It's forming new pathways to help you learn and remember information.
Studies show that a good night's sleep improves learning. Whether you're learning math, how to play the piano, how to perfect your golf swing, or how to drive a car, sleep helps enhance your learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative.
If you're sleep deficient, you may have trouble making decisions, solving problems, controlling your emotions and behavior, and coping with change. Sleep deficiency also has been linked to depression, suicide, and risk-taking behavior.
Children and teens who are sleep deficient may have problems getting along with others. They may feel angry and impulsive, have mood swings, feel sad or depressed, or lack motivation. They also may have problems paying attention, and they may get lower grades and feel stressed.
Sleep plays an important role in your physical health. For example, sleep is involved in healing and repair of your heart and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, andstroke.
Sleep deficiency also increases the risk of obesity. For example, one study of teenagers showed that with each hour of sleep lost, the odds of becoming obese went up. Sleep deficiency increases the risk of obesity in other age groups as well.
Sleep helps maintain a healthy balance of the hormones that make you feel hungry (ghrelin) or full (leptin). When you don't get enough sleep, your level of ghrelin goes up and your level of leptin goes down. This makes you feel hungrier than when you're well-rested.
Sleep also affects how your body reacts to insulin, the hormone that controls your blood glucose (sugar) level. Sleep deficiency results in a higher than normal blood sugar level, which may increase your risk for diabetes.
Sleep also supports healthy growth and development. Deep sleep triggers the body to release the hormone that promotes normal growth in children and teens. This hormone also boosts muscle mass and helps repair cells and tissues in children, teens, and adults. Sleep also plays a role in puberty and fertility.
Your immune system relies on sleep to stay healthy. This system defends your body against foreign or harmful substances. Ongoing sleep deficiency can change the way in which your immune system responds. For example, if you're sleep deficient, you may have trouble fighting common infections.
Daytime Performance and Safety
Getting enough quality sleep at the right times helps you function well throughout the day. People who are sleep deficient are less productive at work and school. They take longer to finish tasks, have a slower reaction time, and make more mistakes.
After several nights of losing sleep—even a loss of just 1–2 hours per night—your ability to function suffers as if you haven't slept at all for a day or two.
Lack of sleep also may lead to microsleep. Microsleep refers to brief moments of sleep that occur when you're normally awake.
How Much Sleep Do You Need?
· Newborns (0-3 months ): Sleep range narrowed to 14-17 hours each day (previously it was 12-18)
· Infants (4-11 months): Sleep range widened two hours to 12-15 hours (previously it was 14-15)
· Toddlers (1-2 years): Sleep range widened by one hour to 11-14 hours (previously it was 12-14)
· Preschoolers (3-5): Sleep range widened by one hour to 10-13 hours (previously it was 11-13)
· School age children (6-13): Sleep range widened by one hour to 9-11 hours (previously it was 10-11)
· Teenagers (14-17): Sleep range widened by one hour to 8-10 hours (previously it was 8.5-9.5)
· Younger adults (18-25): Sleep range is 7-9 hours (new age category)
· Adults (26-64): Sleep range did not change and remains 7-9 hours
· Older adults (65+): Sleep range is 7-8 hours (new age category)
Improve Your Sleep Today: Make Sleep a Priority
Try to keep the following sleep practices on a consistent basis:
1. Stick to the same bedtime and wake up time, even on the weekends.
This helps to regulate your body's clock and could help you fall asleep and stay asleep for the night.
2. Practice a relaxing bedtime ritual.
A relaxing, routine activity right before bedtime conducted away from bright lights helps separate your sleep time from activities that can cause excitement, stress or anxiety which can make it more difficult to fall asleep, get sound and deep sleep or remain asleep.
3. Avoid naps, especially in the afternoon.
Power napping may help you get through the day, but if you find that you can't fall asleep at bedtime, eliminating even short catnaps may help.
4. Exercise daily.
Vigorous exercise is best, but even light exercise is better than no activity. Exercise at any time of day, but not at the expense of your sleep.
5. Evaluate your room.
Design your sleep environment to establish the conditions you need for sleep. Your bedroom should be cool – between 60 and 67 degrees. Your bedroom should also be free from any noise that can disturb your sleep. Finally, your bedroom should be free from any light. Check your room for noises or other distractions. This includes a bed partner's sleep disruptions such as snoring. Consider using blackout curtains, eye shades, ear plugs, "white noise" machines, humidifiers, fans and other devices.
6. Sleep on a comfortable mattress and pillows.
Make sure your mattress is comfortable and supportive. The one you have been using for years may have exceeded its life expectancy – about 9 or 10 years for most good quality mattresses. Have comfortable pillows and make the room attractive and inviting for sleep but also free of allergens that might affect you and objects that might cause you to slip or fall if you have to get up during the night.
7. Use bright light to help manage your circadian rhythms.
Avoid bright light in the evening and expose yourself to sunlight in the morning. This will keep your circadian rhythms in check.
8. Avoid alcohol, cigarettes, and heavy meals in the evening.
Alcohol, cigarettes and caffeine can disrupt sleep. Eating big or spicy meals can cause discomfort from indigestion that can make it hard to sleep. It is good to finish eating at least 2-3 hours before bedtime.
9. Wind down. Your body needs time to shift into sleep mode, so spend the last hour before bed doing a calming activity such as reading.
For some people, using an electronic device such as a laptop can make it hard to fall asleep, because the particular type of light emanating from the screens of these devices is activating to the brain. If you have trouble sleeping, avoid electronics before bed or in the middle of the night.
10. If you can't sleep, go into another room and do something relaxing until you feel tired.
It is best to take work materials, computers and televisions out of the sleeping environment. Use your bed only for sleep and sex to strengthen the association between bed and sleep. If you associate a particular activity or item with anxiety about sleeping, omit it from your bedtime routine.
If you’re still having trouble sleeping, don’t hesitate to speak with your doctor or to find a sleep professional. You may also benefit from recording your sleep in a Sleep Diary to help you better evaluate common patterns or issues you may see with your sleep or sleeping habits.
What Are the Signs and Symptoms of Problem Sleepiness?
Sleep deficiency can cause you to feel very tired during the day. You may not feel refreshed and alert when you wake up. Sleep deficiency also can interfere with work, school, driving, and social functioning.
How sleepy you feel during the day can help you figure out whether you're having symptoms of problem sleepiness. You might be sleep deficient if you often feel like you could doze off while:
- · Sitting and reading or watching TV
- · Sitting still in a public place, such as a movie theater, meeting, or classroom
- · Riding in a car for an hour without stopping
- · Sitting and talking to someone
- · Sitting quietly after lunch
- · Sitting in traffic for a few minutes
Sleep deficiency can cause problems with learning, focusing, and reacting. You may have trouble making decisions, solving problems, remembering things, controlling your emotions and behavior, and coping with change. You may take longer to finish tasks, have a slower reaction time, and make more mistakes.
The signs and symptoms of sleep deficiency may differ between children and adults. Children who are sleep deficient might be overly active and have problems paying attention. They also might misbehave, and their school performance can suffer.
Sleep-deficient children may feel angry and impulsive, have mood swings, feel sad or depressed, or lack motivation.