DEAR MAYO CLINIC: My 14-year-old daughter goes to bed each night around 10 p.m. Some nights she complains that she cannot fall asleep until hours later. Although she wakes up and says she isn't tired, she does sleep in on weekends. I'm concerned about insomnia, but I'm also worried it's affecting her ability to concentrate in school. What advice do you have?
ANSWER: Lots of children your daughter's age have trouble falling asleep easily at night. Though one might say your daughter has bouts of insomnia, in many cases, the reason for sleep challenges can be traced back to habits a child has developed that interfere with good sleep. Less often, it may be due to a sleep disorder.
Unfortunately, many teens don't get the sleep they need. To be well-rested and to help them stay healthy, teenagers need about eight to 10 hours of sleep each night. Healthy sleep is important for many reasons. It can fight stress, improve mood and attitude, and provide energy. When teens are well-rested, they can concentrate, learn, listen and think better than when they're tired. That can improve school participation and performance. Healthy sleep also contributes to a healthy body, helping it run the way it should.
Sleep challenges plague many teenagers, with about 70% of high school students reporting inadequate sleep on school nights. One of the big reasons is that their body's internal clock shifts during the teen years. In the preteen years, the hormone melatonin, which signals to the body that it's time to sleep, is released into the bloodstream earlier in the evening. In most teens, melatonin levels don't rise until about 10:30 or 11 p.m., so they aren't sleepy before then. But going to bed at that time means teens should ideally sleep until about 7:30 or 8 a.m. This isn't an option for many because of school start times.
More than others, some teens tend to show a preference for the late evening hours. They are actually most energetic, intellectually productive and creative in the late evening. It is important to recognize that this is also a normal pattern. For those with these "night owl" tendencies, however, it is especially important to provide lots of light exposure and physical activity immediately upon awakening in the morning and to have dimmer lighting around the house during the evening hours.
One of the most important things teens can do to sleep well regularly is to set a consistent wake-up time and build a sleep schedule around it. It doesn't have to be exactly the same, but the wake-up time should be within about a two-hour window every day of the week. This allows the body's internal clock to run smoothly and avoid the difficulty of trying to readjust and get up on Monday morning at 6 a.m. after sleeping in until noon on the weekends.
Picking a reasonable bedtime and sticking to that most days can be very useful, too. When teens get up at the same time every day, they will get sleepy around the same time every night. Your daughter should listen to that and go to bed as soon as she feels tired.
There are also ways your daughter can make it easier for her body to sleep. For example, she should stay away from pop, sugar, caffeine and big meals two to three hours before going to bed. She should exercise, but do it at least two hours before bedtime. And she should not nap during the day.
Creating a sleep-friendly environment can make a difference, too. Electronic devices and screens, along with the lights on them, in a teen's room at night often disrupt sleep. Avoid distractions by keeping TVs and computers out of bedrooms. Cellphones should be turned off at bedtime and stored outside the bedroom. For the best sleep, keep bedrooms cool, dark and quiet during the night.
Be mindful of how homework, extracurricular activities and after-school jobs can affect the goals you set. Often teens want to do as much as they can, but if the activities are too time-consuming, it may lead to a more significant amount of lost sleep. If your teen has a job, consider limiting it to no more than 15 hours a week with hours that do not interfere with sleep opportunity. Then it's likely she'll still have enough time for homework and other activities without sacrificing sleep.
Work with your local school district to advocate for later school start times in accordance with the American Academy of Pediatrics and the American Academy of Sleep Medicine recommendations that school should not start before 8:30 a.m. for middle and high school.
If there are persistent problems falling asleep on a regular basis or if there are concerns for poor sleep quality, it is a good idea to work with a sleep specialist. Encourage your daughter to get more sleep each night. When she does, it's quite likely that she'll feel more alert, have more energy and be able to focus more effectively and for longer periods of time at school. — Robin Lloyd, M.D. , Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
