My teenager sleeps less than 8 hours. Is that enough?

For most teenagers, less than 8 hours is not enough. The US CDC, citing a consensus statement of the American Academy of Sleep Medicine, recommends 8 to 10 hours a day for teens aged 13 to 17. Many Thai teens fall short: in a 2016 study of 777 Thai high school students, only 254 slept more than 7 hours, and 56.24% had poor sleep quality. The American Academy of Pediatrics lists biological changes in sleep at puberty, alongside lifestyle and schoolwork, among the reasons teens find it hard to get enough sleep. Keep wake-up times steady through the week, switch screens off at least 30 minutes before bed, keep caffeine out of the afternoon and evening, and talk to a doctor if poor sleep goes on and affects school or daily life.

How much sleep does a teenager need?

The recommended range

The CDC's sleep page lists recommended hours by age, based on a consensus statement of the American Academy of Sleep Medicine:

The American Academy of Pediatrics, in its policy statement on school start times, describes 8.5 to 9.5 hours as the optimal amount for middle and high school students. A Ramathibodi Hospital @Rama magazine column for school-age children suggests 9 to 11 hours of sleep a day, or going to bed by 9 p.m.

So is 7 hours enough?

On these ranges, a 15-year-old who sleeps 7 hours on school nights is at least an hour short of the lower end. One short night is not a problem, but a gap every school night adds up over the week. Needs vary from person to person, so also look at whether your teen gets through the day as usual.

How long do Thai teenagers sleep?

What Thai studies found

Why the numbers differ

The national survey gave one average for a wide age range, from 10-year-olds who tend to sleep longer to 19-year-olds. The central Thailand study looked only at upper secondary students, the group with the earliest school mornings and the most homework, and relied on students' own answers on a sleep questionnaire, which are easy to over- or under-estimate. The school-based studies covered particular schools, not the whole country. Together they suggest that the national average looks fine, but a large share of older teens report sleeping 7 hours or less.

What about social media?

In the central Thailand study, social media was the most common activity before bed among students with poor sleep quality (44.56%) and also among those with good sleep quality (37.38%). Students who used social media spent 3.58 hours a day on it on average. Once the researchers took other factors into account, the link between social media use and poor sleep quality was not statistically clear. The Siriraj study of girls found that poorer sleep quality was linked with social media use. Both studies show links, not proof that phones cause poor sleep.

Why do teenagers stay up late and struggle to wake up?

Their body clock shifts later

The US National Heart, Lung, and Blood Institute (NHLBI) explains that the body's internal clock controls when we feel sleepy, and that it is natural for many teens to prefer later bedtimes and to sleep later in the morning than adults. A Ramathibodi Hospital leaflet on sleep, written by a psychiatrist, describes the same pattern: teenagers tend to feel sleepy late and wake late, so teens in Bangkok who must get up early for school do not get the sleep their body needs, and the shortfall builds up over the week.

Early starts, homework and social life

The American Academy of Pediatrics lists biological changes in sleep at puberty, lifestyle choices and academic demands as factors that make it hard for middle and high school students to get enough sleep, and points to early school start times (before 8:30 a.m.) as a key factor that could be changed. Add a long commute, tutoring after school and homework, and the time left for sleep shrinks.

Screens and light at night

The NHLBI says light from screens before bed may signal the brain that it is time to be awake. For more on phones and falling asleep, see On my phone in bed and can't fall asleep. What can I do?

Caffeine in the evening

The CDC advises avoiding caffeine in the afternoon or evening, and the NHLBI lists caffeinated soda, coffee, tea and chocolate as sources of caffeine. For how long caffeine lasts, see Energy drinks and coffee to study late: what about sleep?

Is it OK to catch up on sleep at weekends?

The Ramathibodi leaflet notes that teenagers who are short of sleep during the week sleep in a lot on days off to make up for it. A very long weekend lie-in is therefore a useful sign: it shows the weekday hours are not enough.

The NHLBI advises keeping the same sleep schedule on weeknights and weekends, and the CDC advises going to bed and getting up at the same time every day. The NHLBI suggests keeping the difference between weekday and weekend sleep times to no more than about an hour.

What can parents do at home?

Know the target and agree on a routine

A 2024 Chulalongkorn University study of 215 caregivers of Thai children aged 3 to 12, by Hongnipon and colleagues, found that caregivers whose expectations matched the right amount of sleep for their child's age reported fewer sleep problems in their children. The study looked at younger children at one point in time, so it cannot show whether one causes the other.

With a teenager, a routine usually works better when it is agreed together. Some practical steps:

• Work back from the time your teen must get up. For an 8-hour minimum with a 6 a.m. alarm, lights out is 10 p.m.
• Keep the wake-up time within the same range every day, including weekends (NHLBI, CDC).
• Use the hour before bed as quiet time, without intense exercise or bright light (NHLBI).

Screens and phones

• The CDC advises turning off electronic devices at least 30 minutes before bedtime.
• Agree on a place outside the bedroom where phones charge overnight, and do it as a family so it is not a punishment. The NHLBI advises not using a child's bedroom for timeouts or punishment.
• If your teen is in group chats late at night, help them mute notifications after a set time.

The bedroom and the daytime

• Keep the bedroom quiet, cool and dark (NHLBI).
• Spend time outside every day and be physically active, as the NHLBI suggests.
• Avoid large meals within a few hours of bedtime and keep caffeine out of the afternoon and evening (CDC, NHLBI).

Talk with your teen about the week

Look at the week together: tutoring, homework, travel and activities. If every evening is full, something has to give, and it is usually sleep. For exam periods, see Too stressed to sleep before exams? How can you relax?

When should my teenager see a doctor about sleep?

The CDC advises talking to a healthcare provider if you regularly have problems sleeping. See a doctor with your teen if:

• they often cannot fall asleep or stay asleep, even with a regular routine and screens off
• they are so sleepy during the day that school, sport or daily life suffers, even after enough hours in bed

If poor sleep comes with low mood or worry that does not lift, talk to a doctor too. In Thailand, the 1323 mental health hotline is free and open 24 hours a day. If your teen takes any medicine or health product, tell the doctor or pharmacist.