Why Do Teenagers Sleep So Much During the Day

Teens 13–17 · Explainer · Updated October 1, 2026 · LearnLife Editorial

Why do teenagers’ internal clocks make them sleep later and feel tired during the day?

During puberty, teenagers experience a shift in their circadian rhythms—the internal biological clock that tells the body when to feel awake or sleepy. This shift delays the release of melatonin, the hormone responsible for making you feel sleepy, pushing it to about 1 or 2 a.m. instead of 9 or 10 p.m. This means that even if a teen wants to fall asleep earlier, their body isn’t ready until much later at night.

For example, a teen might feel wide awake at 11 p.m., but they need to get up by 6:30 a.m. for school. This creates a natural mismatch between when their body wants to sleep and when they have to wake up. Because they get less sleep at night, they often feel sleepy or tired during the day. To cope, many teens nap after school, sometimes for an hour or more.

This shift in sleep timing is not about laziness or staying up late by choice; it’s a biological change that affects almost every teenager. The challenge is that school start times often don’t align with teens’ biological needs, creating “social jetlag,” where their body clock and social schedule don’t match.

How does daytime sleep help teenagers recover and support their health?

Daytime sleep, such as naps or longer rest periods, helps teenagers make up for the lost nighttime sleep caused by late bedtimes and early mornings. Sleep isn’t just about feeling rested; it’s when the brain processes memories, solidifies learning, and the body releases growth hormones essential for development.

For instance, if a teen sleeps only six hours on a school night, they might feel exhausted the next day, affecting focus, mood, and energy. Taking a 30-minute nap after school can reduce tiredness and improve alertness for homework or activities. Longer naps or sleeping in on weekends helps to “pay back” lost sleep, which is important for mental and physical health.

However, it’s best if daytime sleep is used strategically. Short naps (20-30 minutes) boost energy without interfering with nighttime sleep, whereas long naps (over an hour) late in the day might delay bedtime further, making the cycle worse.

How does early school start time impact teens’ sleep patterns and daytime sleep?

Many schools start classes early, sometimes as early as 7:30 a.m., requiring teens to wake up well before their natural wake time. Since teens’ internal clocks push them to sleep later, they don’t get enough sleep if they must wake early for school.

For example, a teen who falls asleep at 12:30 a.m. but must be up by 6:30 a.m. gets only 6 hours of sleep, 2 to 4 hours less than recommended. This sleep debt builds up over the week, causing teens to feel extremely sleepy during the day and making it harder to focus in class. To compensate, many teens find themselves napping after school or feeling drowsy in the afternoon.

Some school districts have considered or adopted later start times to help teens get more sleep, which can reduce daytime sleepiness and improve academic performance, mood, and overall health. If changing school start times isn’t an option, teens can try to adjust their schedules and habits to improve sleep quality.

What practical habits can teens adopt to improve nighttime sleep and reduce daytime sleepiness?

Improving sleep quality at night can reduce the need for long daytime naps. Here are specific habits teens can try:

• Set a consistent bedtime and wake-up time. For example, go to bed at 10:30 p.m. and wake at 7 a.m. each day, including weekends, to train your internal clock.
• Create a relaxing pre-sleep routine. Try reading a book, meditating, or listening to calming music to signal your body that it’s time to wind down.
• Turn off screens at least an hour before bed. The blue light from phones and computers suppresses melatonin and tricks the brain into thinking it’s daytime.
• Get sunlight exposure during the day, especially in the morning. This helps reset the body clock and improves alertness.
• Limit caffeine intake after noon. For example, avoid energy drinks or sodas after lunchtime to prevent sleep disruption.
• Exercise regularly but avoid vigorous workouts close to bedtime. Physical activity earlier in the day can help you fall asleep easier at night.
• Avoid heavy or large meals late in the evening. Eating a big meal near bedtime can make it harder to fall asleep.

Adopting these habits consistently can help teens fall asleep earlier, sleep better, and feel less tired during the day.

How can teens balance daytime naps with nighttime sleep?

Napping can be helpful but requires balance. Short naps of 20-30 minutes can boost alertness and reduce sleepiness without making it harder to sleep at night. These naps are best taken earlier in the afternoon, no later than 3 p.m.

Long naps or sleeping late into the afternoon can make it difficult to fall asleep at bedtime, worsening the cycle of poor nighttime sleep and daytime tiredness. For example, a teen who naps for 90 minutes at 5 p.m. might not feel sleepy until very late at night, pushing their bedtime closer to 2 a.m.

If daytime sleepiness is overwhelming, it’s better to work on improving nighttime sleep habits first and use naps sparingly. Keeping a sleep diary to track sleep times and naps can help teens understand how naps affect their nighttime rest.

What are some sleep problems or disorders that might cause excessive daytime sleep in teens?

While most daytime sleepiness in teens is due to natural body clock shifts and sleep loss, excessive sleepiness can sometimes signal a sleep disorder. Conditions like obstructive sleep apnea (snoring and breathing pauses during sleep), narcolepsy (sudden daytime sleep attacks), or insomnia can interfere with restful sleep.

Warning signs that a teen should see a healthcare provider include:

• Falling asleep unexpectedly during classes or activities.
• Loud snoring, gasping, or choking during sleep.
• Difficulty waking up in the morning despite enough time in bed.
• Mood swings, irritability, or problems concentrating.
• Sleeping more than 10-12 hours regularly but still feeling tired.

If any of these symptoms appear, talking to a doctor or sleep specialist is important. Early diagnosis and treatment can improve energy, mood, and overall health.

How can families and schools support teens’ sleep needs and reduce daytime sleepiness?

Families can support teens by understanding their biological sleep changes and encouraging healthy habits. Avoid pressuring teens to go to bed very early if their body clock isn’t ready, and help create a calm bedroom environment. Parents can limit screen time before bed and encourage physical activity during the day.

Schools can help by considering later start times or scheduling demanding classes later in the morning. Educators can also educate students about sleep’s importance and offer breaks to reduce daytime fatigue.

Teens should communicate openly about their sleep needs with parents and teachers. For instance, if a teen feels excessively tired, they can say, “I’ve been struggling to fall asleep early because my body feels awake late, and waking up early for school makes me sleepy during the day.” This can open conversations about possible solutions.

Combining family support and school policies can create an environment where teens get better sleep and feel more alert and ready to learn.

Frequently asked questions

Can sleeping too much during the day make it harder to sleep at night?

Yes. Long or late naps can delay your ability to fall asleep at night, making you more tired during the day. Short naps earlier in the afternoon are better for boosting energy without disrupting nighttime sleep.

Why do teens feel more awake at night but tired during the day?

Because their internal clocks shift during puberty, teens naturally feel alert later at night and sleepy later in the morning. Early school times force them to wake up before their bodies are ready, causing daytime tiredness.

Is it okay for a teen to sleep more than 10 hours a night?

Occasionally sleeping longer can help recover lost sleep, but regularly sleeping over 10 hours might signal a sleep problem or illness, so it’s good to talk to a healthcare provider if this happens.

What should I do if I can’t stop feeling sleepy during the day?

Try improving your sleep routine at night, limit naps, and get morning sunlight. If sleepiness continues, tell a parent or doctor to check for possible sleep disorders or other health issues.

How can I convince my parents or school to help with my sleep schedule?

Explain how your shifted sleep times affect your energy and school performance. Suggest small changes like limiting screen time or adjusting school start times. Sharing information about teen sleep biology can help them understand your situation.