Teen Can't Sleep at Night? Why It Happens and What Helps

It is past midnight. You get up for a glass of water and there it is again: the thin line of light under your teenager’s door. They are not partying. They say they just can’t sleep. And in six and a half hours you will be dragging them out of bed for school, both of you already tired and short-tempered. If your teen can’t sleep at night, you are not raising a lazy kid, and they are not doing it to annoy you.

Here is the short answer. During puberty a teen’s body clock really does shift later, so feeling wide awake at 11pm is normal biology, not bad behavior. You cannot force an early bedtime against that clock, but you can move it. Keep the wake-up time the same every day, weekends included. Get them into bright daylight soon after they wake. Stop caffeine after lunch, and charge the phone outside the bedroom. If they lie awake longer than about 20 minutes, they get up, do something quiet in dim light, and come back when sleepy. Give it two weeks before you judge it.

Lying awake yourself, worrying about them? Start with your own night.

No password. We email you the link, and one tap opens your reset.

Why your teen can’t sleep at night

This is the part most parents never get told. Around the start of puberty, most kids go through what sleep doctors call a “phase delay.” The American Academy of Pediatrics describes a shift of up to 2 hours later compared with how they slept in middle childhood.

The AAP names two reasons:

Melatonin comes later. The body releases its own sleep signal later in the evening, so the brain simply does not feel sleepy at the old bedtime.
Sleep pressure builds more slowly. The urge to sleep that piles up during the day takes longer to get heavy, so staying up late feels easy.

Put together, the AAP says the average teenager has a hard time falling asleep before 11pm and is best suited to waking at 8am or later. Now picture a 6:30 alarm for a 7:30 bus. That gap is where the trouble lives.

So when your 15-year-old says “I’m not tired” at 10pm, they are probably telling the truth. The goal is not to win an argument about bedtime. It is to slowly pull their clock earlier.

How much sleep does a teenager actually need?

More than most of them get. The CDC passes on the American Academy of Sleep Medicine’s advice: 8 to 10 hours per 24 hours for ages 13 to 18. The AAP puts the sweet spot at 8.5 to 9.5 hours a night.

Do the math with a real school night. Asleep at 11:45pm, alarm at 6:30am. That is under 7 hours, before you count the time it took to drop off. Do that five nights in a row and Friday’s teenager is foggy, snappy and running on energy drinks.

The AAP also points out that naps, weekend lie-ins and caffeine can hide the sleepiness for a while, but they do not bring back real alertness. Only regular, enough sleep does that.

Body clock, or something else?

For most teens, it is the normal shift plus a phone and a busy schedule. For some it goes further.

Delayed sleep phase. When the clock gets stuck very late, so a teen cannot fall asleep until 1am or 2am even when they try, it can be a circadian rhythm disorder. The American Academy of Sleep Medicine says delayed sleep-wake phase disorder may affect about 7% to 16% of teens and young adults, and that both too little morning sunlight and too much bright evening light can make it worse. Cleveland Clinic notes it is more common in adolescents because the body clock changes during puberty. If that sounds like your house, our guide on how to fix delayed sleep phase walks through a two-week plan.

A worried or low mind. The American Academy of Child and Adolescent Psychiatry lists mood problems, anxiety, ADHD, past trauma and substance use as things that can sit behind teen sleep trouble. A teen who used to sleep fine and now lies awake every night, or seems flat and withdrawn in the day, deserves a gentle conversation and maybe a doctor’s visit.

Too much in the evening. Homework at 10pm, late sports practice, a gaming session, a group chat that never ends. None of this is a disorder. It just keeps the brain switched on right when it should be winding down.

What helps tonight, while they’re lying awake

You cannot fix the clock in one night. You can make tonight easier.

Get out of bed after about 20 minutes. The AACAP advises that if a child cannot fall asleep within 15 to 20 minutes, they get up, do something quiet and relaxing, and only go back to bed when sleepy. Lying there getting frustrated teaches the brain that bed is a place for being awake.
Keep the light low and the phone away. A paper book, a lamp turned down, soft music. Not the phone. A bright screen at 1am is exactly the kind of evening light that pushes the clock later.
Empty the head onto paper. Many teens lie awake replaying a text, a test, a fight. Two minutes writing it down, plus “I’ll deal with it after school,” often loosens the grip.
Breathe out longer than in. In through the nose for a count of 4, out slowly through the mouth for 6 to 8. Ten rounds. A lot of people find a long, slow exhale is the quickest way to feel their body start to settle. It is the same idea behind our free 5-minute sleep reset, and it works for teens and tired parents alike.

Got a big test tomorrow? Our page on how to sleep the night before an exam is written for exactly that night.

A two-week plan to move their sleep earlier

This is the real fix. It is boring, and it works best when your teen helps plan it instead of having it handed to them.

1. Anchor the wake-up time

Pick one wake time and keep it seven days a week. Nationwide Children’s Hospital suggests bedtime and wake time should not differ by more than about an hour from one day to the next, and advises against sleeping in on weekends to “catch up,” because that makes falling asleep harder at bedtime. The AACAP gives a little more room: weekends within 1 to 2 hours of school days.

The wake time comes first. Bedtime follows it, because a teen who got up at 7 on Saturday will feel sleepy earlier on Sunday than one who slept until noon.

2. Morning light, fast

Nationwide Children’s says time outside every day, especially in the morning, helps keep the body clock on track. Open the curtains as soon as they are up. Breakfast by the window. Walk or bike to the bus if you can. On dark winter mornings, put on every light in the kitchen.

3. Caffeine stops at lunch

HealthyChildren.org, the AAP’s site for parents, says caffeine can stay in the body for more than 8 hours and advises teens to avoid it after lunchtime. That includes iced coffee, cola, sweet tea, chocolate and the energy drinks that many teens treat like water. The AACAP specifically says no caffeinated or energy drinks within 6 hours of bed.

4. Phones sleep in the kitchen

HealthyChildren.org recommends putting screens away at least an hour before bed and charging devices outside the bedroom overnight. The light can push the body’s own melatonin later, and the buzz of a late message is hard for anyone to ignore, let alone a 14-year-old. Our guide on how to stop using your phone before bed has ideas that work for adults too, which helps if the whole family does it.

5. Move bedtime in small steps

If they fall asleep at 12:30 now, aiming for 10pm tomorrow will just mean two hours of staring at the ceiling. Move “lights out” about 15 minutes earlier every few nights, and only once falling asleep at the current time feels easy. Slow is the fast way here. The same idea is laid out step by step in how to sleep earlier after being a night owl.

6. A short nap, or none

Coming home from school and sleeping until 7pm wrecks the night. Nationwide Children’s suggests that if a teen is very sleepy, a nap of 15 to 20 minutes in the early afternoon is fine, but long or late naps make bedtime harder.

7. A bed that is only for sleep

Both the AACAP and HealthyChildren.org suggest keeping homework, gaming and TV out of bed, so the brain links lying down with sleep. A cool, dark, quiet room helps too. A desk or a beanbag for homework is worth the space.

How to talk about it without a fight

Teens hear “go to bed” as “you are a child.” That is a fight you lose before it starts.

What tends to go better is treating it as their problem to solve, with you on their side. Share the body clock part first. It is a relief for a lot of teens to hear that their brain really is wired to feel awake late, and that it is not a character flaw. Then ask what they care about. Making the team. Not falling asleep in first period. Having more energy at practice. Let them pick the wake time and the phone parking spot.

And go first. If your phone comes to bed with you every night, they will notice. A family “phones charge in the kitchen at 9:30” rule lands very differently from a rule that only applies to them.

What about melatonin?

It is tempting. The gummies are everywhere. But the American Academy of Sleep Medicine advises parents to talk to a pediatric health professional before giving melatonin or any supplement to children and teens. It points out that in the US melatonin is sold as a dietary supplement without the oversight that medicines get, and that in one study the real amount in products ranged from under half to more than four times what the label said. Chewable tablets varied the most.

The AASM also says many sleep problems are better handled with changes to schedules and habits than with melatonin. If a doctor does suggest it, they can tell you the dose and the timing. For a wider look, see is melatonin bad for sleep.

When to see a doctor

Talk to your teen’s doctor if:

They still cannot fall asleep until very late after a few weeks of a steady wake time and morning light.
Sleep problems are causing missed school, falling grades or trouble waking at all.
They seem low, anxious, irritable or withdrawn, or you are worried about alcohol, vaping or other substances. The AACAP lists all of these as possible causes.
They drive and are often drowsy. Nationwide Children’s warns that teenagers are at the highest risk of falling asleep at the wheel.

Not sure whether it has crossed the line from a rough patch into something more? How to know if you have insomnia explains what doctors look for.

And what about your nights?

Here is the quiet part. Plenty of parents who search this at midnight are not only worried about their teen. They are lying awake too, listening for footsteps, running tomorrow’s morning battle in their head. Your sleep matters in this as well. A rested parent is calmer at 7am, and calm is contagious.

If your own body won’t power down, start with five minutes in bed tonight.

Quick answers

Why can’t my teenager sleep at night but sleeps all day?

Usually because the body clock has drifted late, and long lie-ins or afternoon naps keep it there. The AACAP calls this sleep-wake reversal and says it is common in teens. A fixed wake time and morning light are the main levers to bring it back.

Is it normal for a 15-year-old not to feel tired until midnight?

Feeling awake until around 11pm is normal for many teens, according to the AAP. Regularly not being able to sleep until well after midnight, even when trying, is worth working on with the plan above, and with a doctor if it doesn’t shift.

Should I take my teen’s phone at night?

The AAP’s parent site recommends charging devices outside the bedroom overnight. It tends to go better as a family rule that your teen helps set, rather than a punishment.

Will sleeping in on the weekend help them catch up?

A little extra is fine, but Nationwide Children’s advises against big weekend lie-ins because they make falling asleep harder on Sunday night. Keep weekend wake-ups within about an hour or two of school days.

Sleep that comes easier, for both of you

Want to fall asleep easier yourself? Grab the free 5-minute sleep reset.