Why is sleep so important?
For a child, sleep is not passive rest but an active developmental process. During sleep the brain consolidates what it has learned during the day, the body repairs itself and immunity strengthens. A critical detail for growth is this: most of the growth hormone that drives growth is released during the deep-sleep stages of the night. So adequate, good-quality sleep is an unseen but fundamental pillar of healthy growth.
Insufficient sleep, on the other hand, is linked with difficulty in attention and learning, mood swings, appetite irregularity and, in the long term, health problems. Sleep is a health behaviour as important as nutrition and movement.
Sleep needs by age
Sleep needs change with age. The widely accepted recommendations are as follows: for preschool (ages 3–5), about 10–13 hours a day (including daytime naps); for school age (ages 6–12), 9–12 hours; for adolescents (ages 13–18), 8–10 hours. These figures refer to the 24-hour total and are weighted toward night-time sleep.
Alongside duration, regularity matters too: going to bed and waking at similar times on weekdays and weekends balances the body’s internal clock. In adolescents especially, the biological clock naturally shifts toward later bedtimes; when this clashes with school hours, a sleep debt can build up. Where possible, a consistent sleep–wake rhythm should be maintained.
Practical principles for healthy sleep
The strongest supporter of good sleep is a consistent routine: a similar bedtime each day and a calming pre-bed routine (a warm bath, a book, dim light). One of the biggest obstacles is screens; using screens in the hour before bed both delays falling asleep and lowers sleep quality. So keeping the bedroom screen-free and switching screens off in the hour before bed is very effective.
Other supports: enough physical activity and daylight during the day; avoiding heavy evening meals, caffeine (cola, tea) and over-stimulation; and keeping the bedroom cool, dark and quiet. If sleep problems are persistent and impair daytime functioning (constant tiredness, snoring/pauses in breathing, inability to fall asleep), they should be assessed with a health professional.
Sleep and school hours in adolescents
In adolescence, sleep needs particular attention. At puberty the biological clock naturally shifts later; that is, adolescents become sleepy later and struggle to wake early in the morning. This is not “laziness” but a biological change. Combined with early school start times, many adolescents build up a chronic sleep debt, which adversely affects attention, mood, learning and even immunity.
In this period, realistic supports work better than a single rule: limiting screens and caffeine in the evening, keeping weekday and weekend sleep times as close as possible, getting morning daylight, and making the bedroom sleep-friendly (cool, dark, screen-free). A few hours of weekend recovery can help, but large shifts in timing disrupt the internal clock even more. If persistent sleeplessness is impairing daytime functioning, a doctor should be consulted about an underlying sleep problem.