Sleep hygiene: the tips everyone should know

What sleep hygiene is — and what it is not

“Sleep hygiene” is the set of everyday habits and conditions that make good sleep more likely: when you wake, how much daylight you get, what you drink in the afternoon, how bright your evening is, what your bedroom is like, and what you do when you cannot sleep. The habits are unglamorous and the evidence for each one, taken alone, is modest. Together, kept up for weeks, they are the foundation every other approach to sleep rests on.

They are not a treatment for a sleep disorder. That is not a disclaimer; it is what the evidence says. Reviews of sleep hygiene education as a stand-alone treatment for insomnia find only small effects, and the American Academy of Sleep Medicine’s 2021 guideline recommends against using it as a single-component treatment for chronic insomnia. The recommended treatment is cognitive behavioural therapy for insomnia, which uses several of these habits inside a structured programme. So: do these first, but if sleep is still poor after three or four consistent weeks, that is information for a doctor, not a reason to try harder.

The eight habits that matter most

1. Wake at the same time every day

Your body clock decides when you can fall asleep, and it is set by when you get up and see light, not by when you go to bed. Keeping the wake time fixed — within about an hour, including weekends — is the habit sleep-medicine guidance puts first. Irregular sleep timing is associated with a later, weaker circadian rhythm and worse daytime functioning even when total sleep is similar. If you want to change your schedule, move the wake time first; bedtime follows.

2. Get daylight within an hour of waking

Morning light is the strongest signal that anchors the clock: light after waking pulls it earlier, light late in the evening pushes it later. Ten to twenty minutes outdoors soon after waking is enough on most days, and it matters most in winter and for anyone who works indoors. A bright window is a weak substitute; outdoor light is many times brighter even on an overcast day.

3. Move during the day

Across dozens of studies, regular physical activity modestly improves how quickly people fall asleep, how much deep sleep they get and how they rate their sleep. Intensity and timing matter less than people fear: for most, exercise in the evening does not harm sleep, though a hard session in the last hour before bed can delay it. The practical rule is regular movement, ideally with some of it outdoors.

4. Stop caffeine six to eight hours before bed

Caffeine lasts longer than it feels. In a controlled study, 400 mg of caffeine — roughly two large coffees — taken six hours before bed still reduced sleep by about an hour and made it lighter, even though participants did not notice. For most people a cut-off six to eight hours before bed works; if you are sensitive, or if you find yourself waking early, move it earlier. Tea, cola, energy drinks and some pain relievers count.

5. Be careful with evening alcohol

Alcohol is a sedative, which is why it helps you drop off. It is also metabolised within a few hours, and as it wears off the second half of the night becomes lighter, more fragmented and shorter on REM sleep. Regular use builds tolerance to the sedative effect while the fragmentation remains. If you drink, finishing three or more hours before bed limits the damage.

6. Dim the evening and put screens down

Light in the evening delays the clock and suppresses melatonin, and people vary enormously in how sensitive they are: in one study, a dim living-room level of light was enough to halve melatonin in the most sensitive participants. Lower the lights in the last hour or two, keep screens out of the last 30 to 60 minutes, and if you must use one, turn the brightness down and hold it further away.

7. Keep the bedroom dark, quiet and cool

Light and noise cause brief arousals you do not remember but that fragment sleep; blackout blinds, an eye mask or earplugs are cheap fixes. Temperature is the underrated one: falling asleep depends on a small drop in core body temperature, and a warm room works against it. Most people sleep best in a room that feels slightly cool — many guides suggest roughly 18 to 20 °C — with bedding you can adjust.

8. Keep the bed for sleep

Your brain learns what the bed is for. Working, scrolling and, above all, long stretches of lying awake teach it that bed is a place for being awake. If you have been awake for what feels like 20 minutes or more, get up, do something calm in dim light, and go back when sleepy. This is stimulus control, one of the core techniques of CBT-I, and it is the habit people most often skip because it feels counter-intuitive.

The mistakes that quietly undo it

• The weekend reset. Sleeping in two hours on Saturday and Sunday shifts the clock the way a westward flight does, and Monday feels like jet lag.
• Going to bed early to “catch up”. More time in bed with the same amount of sleep lowers sleep efficiency and weakens the bed–sleep link. Anchor the wake time instead.
• Long or late naps. A short nap before mid-afternoon is fine; an hour at 5 pm spends the sleep pressure you need at 11.
• Treating the list as a cure. If you snore loudly, gasp at night, are sleepy enough to doze in the day, or have had trouble sleeping most nights for three months, no habit fixes that.

When habits are not enough

See a doctor if poor sleep has lasted more than a few weeks despite consistent habits, if you are sleepy enough to doze off during the day (and do not drive until you have been assessed if you have dozed at the wheel), if you snore loudly or stop breathing in your sleep, or if you feel low most days. Our guides to insomnia and to sleep apnea explain what an assessment involves.