Sleep hygiene: the habits with the best evidence

Sleep hygiene means the everyday habits that make good sleep more likely, such as a regular wake-up time and an early cut-off for caffeine. Most of these habits are linked to better sleep in research, but the evidence is stronger for some than others. If you have ongoing insomnia, habits alone usually aren't enough.

What does the research say about sleep hygiene?

A 2015 review in Sleep Medicine Reviews looked at the evidence behind common sleep hygiene advice on exercise, stress, noise, sleep timing, caffeine, nicotine, alcohol and napping. Its overall finding was mixed. Studies generally supported a link between each individual habit and how people sleep at night. But the direct effect of following each recommendation had mostly not been tested in the general population.

So the habits make sense and point in the right direction. What's less clear is how much any single change will help a particular person.

Which habits do sleep experts recommend?

The American Academy of Sleep Medicine (AASM) and the CDC give very similar lists. The AASM's version includes:

• Get up at the same time every day, including weekends and holidays.
• Set a bedtime early enough to get at least 7 to 8 hours of sleep.
• Only go to bed when you feel sleepy.
• If you haven't fallen asleep after 20 minutes, get up and do something quiet in low light, without electronics.
• Use your bed only for sleep and sex.
• Keep the bedroom quiet, relaxing and at a comfortable, cool temperature.
• Limit bright light in the evening, and turn off devices at least 30 minutes before bed.
• Avoid a large meal before bed, and limit how much you drink in the evening.
• Avoid caffeine in the afternoon and evening, and alcohol before bed.
• Exercise regularly.

The CDC's list adds little beyond this. It recommends the same consistent sleep and wake times, a cool and quiet bedroom, switching off devices 30 minutes before bed, and avoiding large meals, alcohol and late caffeine.

Which habits have the strongest evidence?

Of the sleep hygiene habits, caffeine timing has some of the strongest evidence. In a 2013 study in the Journal of Clinical Sleep Medicine, 400 mg of caffeine taken 6 hours before bed still reduced measured sleep by more than an hour, even though participants didn't notice it in their sleep diaries. The authors said this supports avoiding substantial caffeine for at least 6 hours before bed.

Alcohol is also well studied. A 2013 review of studies in healthy volunteers found that at all doses, alcohol helps people fall asleep faster and makes the first half of the night more settled, but increases sleep disruption in the second half. It also delays the first period of REM sleep. If alcohol also makes you snore, see alcohol and snoring.

Nicotine belongs on the list too. The 2015 review found nicotine use is linked to taking longer to fall asleep, sleeping less and waking earlier, and that smokers sleep worse than nonsmokers even after years of smoking. Quitting can disrupt sleep for a while, because withdrawal symptoms peak a few days in and last three to four weeks. That's worth knowing so a few rough nights don't feel like failure.

The same review adds a useful detail on caffeine. Large doses close to bedtime clearly disrupt sleep, but the effects of smaller doses are less consistent, and giving up caffeine may help light or occasional users more than habitual coffee drinkers. For most people, an earlier cut-off matters more than quitting. The NHS suggests no tea, coffee, alcohol or smoking for at least 6 hours before bed.

Does exercise help you sleep?

Exercise does seem to help you sleep, though the details are fuzzy. The 2015 review describes two meta-analyses in which a single bout of exercise led to modest increases in total sleep time and deep sleep, and a small reduction in the time it took to fall asleep. The largest increases in sleep time came after sessions longer than 60 minutes. The type of exercise and how fit people were didn't make much difference.

There are limits. Most of these studies looked at young adults who already slept well, and the review says there isn't enough research yet to give specific advice on the best type, amount or timing of exercise for sleep. Regular activity at a time that suits you is a reasonable approach.

Are naps bad for your sleep?

Naps are less bad for your sleep than you might think. The 2015 review found that most research, mainly in older adults, showed no significant link between daytime napping and how people slept at night. Short naps of under 30 minutes are clearly good for alertness, mood and performance.

Long naps are a different story. In one study, older adults who took a 90-minute afternoon nap every day for two weeks slept less and less efficiently at night, measured with overnight sleep recordings, than when they skipped naps. The authors also note that evening naps may be a particular problem, because they can use up the sleep pressure you need at bedtime. If you struggle to fall asleep at night, keeping naps short and early is a sensible test.

Does noise matter if you're used to it?

Noise may matter more than you notice, even if you're used to it. The 2015 review says noise during the night increases arousals and makes sleep lighter, even when it's the ordinary background of traffic, music or plumbing. In lab studies, people seemed to get used to the noise within a few days, but their bodies' arousal responses and their own sleep complaints weren't shown to settle down in the same way.

Earplugs and white noise have both been shown to improve sleep in hospital intensive care patients, and steps to cut traffic noise at home have led to modest improvements. The NHS suggests curtains, blinds, an eye mask or earplugs if your room isn't dark and quiet enough.

Why does getting out of bed help?

Getting out of bed helps because it stops your bed from becoming a place where you lie awake. Two of the habits on the AASM list, going to bed only when sleepy and getting up if you can't sleep, come from a technique called stimulus control. The idea is to stop your bed becoming a place where you lie awake.

This is one of the few habits that has been tested as a treatment. In its 2021 guideline on behavioral treatments for chronic insomnia, the AASM suggests clinicians use stimulus control as a standalone therapy for adults. It also suggests sleep restriction therapy and relaxation therapy on their own.

Is sleep hygiene enough to fix insomnia?

Sleep hygiene usually isn't enough to fix insomnia on its own. The same 2021 AASM guideline suggests clinicians not use sleep hygiene as a single-component therapy for chronic insomnia in adults. Its strongest recommendation is cognitive behavioral therapy for insomnia, often called CBT-I, which combines several techniques.

That doesn't make sleep hygiene useless. The AASM describes it as an important part of CBT for insomnia. But if you've been sleeping badly for a long time and tidying up your habits hasn't helped, it's worth asking a doctor about CBT-I rather than adding more tips.

Does how you breathe at night belong on the list?

How you breathe at night does belong on the list, even though it's rarely on standard sleep hygiene lists. The NHS names snoring and interrupted breathing among the things that keep people from a good night's sleep. If you often wake with a dry mouth or a scratchy throat, or a partner says you snore with your mouth open, how you breathe overnight is worth a look.

Nasal breathing warms and humidifies the air you breathe and helps filter allergens, as the Sleep Foundation points out. If your nose feels blocked at night, start there, and a nasal strip is an easy thing to try. If your nose is clear but your mouth falls open, some adults use mouth tape to keep their lips closed while they sleep. The research on tape is still limited, and it isn't for anyone with a blocked nose or untreated sleep apnea, but for a mouth breather with a clear nose it can be a simple experiment. Take the nose test first, and see how to start mouth taping.

If you want to try mouth tape and nasal strips together, our pick is the Titan Sleep System, which pairs TitanAir Nasal Strips with Titan Mouth Tape.

How should you start?

To start improving your sleep hygiene, pick one or two habits that clearly apply to you rather than trying everything at once. For many people that means a fixed wake-up time and an earlier last coffee. Give each change a couple of weeks before deciding whether it's helping.

If your poor sleep comes with loud snoring or gasping, a new routine isn't the answer. Read our guide to snoring vs. sleep apnea and talk to a doctor.

Read next

• How much sleep do adults need?
• Does slow breathing before bed help you fall asleep?
• Why do I wake up at 3am?

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.