12 common sleep myths, checked against the research

Most adults can't stay healthy on five hours of sleep, a nightcap disrupts sleep rather than deepening it, and lying awake in bed for hours tends to make insomnia worse. Those are three of the sleep myths a panel of sleep experts singled out in a 2019 study. Here are twelve common beliefs, what the research says about each, and a few simple habits that follow from it.

Where do these sleep myths come from?

Most of these sleep myths come from a 2019 study in the journal Sleep Health. Researchers searched popular articles for common beliefs about sleep, then asked ten sleep experts to rate each one on how false it is and how much it matters for public health. Twenty statements were confirmed as myths. The experts didn't agree equally on all of them, and we say so where the evidence is mixed.

Myths about how much sleep you need

Many adults only need five hours or less

The belief that many adults need only five hours of sleep or less is the myth the experts rated most important to correct. Habitual short sleep of 5 hours or less is linked with problems in heart, metabolic, mental and immune health. The study notes that a small minority of short sleepers may cope with less, but most adults need at least 7 hours. The National Heart, Lung, and Blood Institute (NHLBI) lists 7 to 8 hours a day for adults. Our guide to how much sleep adults need goes further.

Your body learns to function on less sleep

Your body doesn't really learn to function on less sleep. People feel like they adjust, but the tests say otherwise. When sleep is restricted, people's own sleepiness ratings level off after a few days, while objective measures of their ability to stay awake keep getting worse. The experts concluded that people may get used to a sleep debt, but at a real cost to health and performance.

You can catch up on sleep at the weekend

Catching up on sleep at the weekend is only partly a myth, and the experts were split on it. The NHLBI says extra sleep on days off might help you feel better but can upset your sleep-wake rhythm, and that sleeping much more on days off may be a sign you aren't getting enough during the week. In a 2019 lab study, young adults who slept 5 hours a night during the week and then slept as long as they liked at the weekend still lost insulin sensitivity once the short nights resumed. A steady schedule works better than a weekend top-up.

Older adults need less sleep

Older adults do tend to sleep less, partly because of health conditions that disturb sleep. But the 2019 study says it isn't evident that they need less than younger adults, only that they get less. If you're older and tired during the day, it's worth looking for the cause rather than accepting it as normal.

Falling asleep anywhere means you're a great sleeper

Being able to nod off anytime and anywhere is more often a sign of a problem. The experts rated this a strong myth, explaining that it usually reflects a chronic lack of sleep and can be a main symptom of obstructive sleep apnea. If you doze in meetings or in front of the TV after a full night in bed, that's worth raising with a doctor.

Myths about bedtime habits

A nightcap helps you sleep

Alcohol may help you fall asleep faster, but it disturbs sleep in the second half of the night and delays REM sleep. The experts also noted that alcohol worsens sleep apnea symptoms. The Sleep Foundation reports that in data from roughly 160,000 of its users' sleep profiles, nearly 90% of people who regularly drink in the evening reported at least one sleep problem. It adds that drinking before bed can worsen snoring by relaxing the throat muscles, and that experts recommend avoiding alcohol within three to four hours of bedtime.

If you can't sleep, stay in bed and keep trying

Staying in bed and trying to sleep feels logical, but it tends to backfire. The approach sleep specialists use instead is called stimulus control: get up, do something calm without bright light, and go back to bed when you feel sleepy. The American Academy of Sleep Medicine (AASM) suggests getting out of bed if you haven't fallen asleep after 20 minutes and staying off electronics while you're up. This is part of cognitive behavioral therapy for insomnia, which the AASM calls the most effective long-term treatment for chronic insomnia.

Lying in bed with your eyes closed is almost as good as sleep

Lying in bed with your eyes closed is not almost as good as sleep, and the experts rated this one strongly false. Brain activity during sleep follows a very different pattern from wakefulness, and the night-time dip in core body temperature is much larger when you're asleep than when you lie quietly awake. Resting has value, but it isn't a substitute for sleep.

Watching TV in bed helps you wind down

The study cites survey data showing that half of US adults watched TV in the 30 minutes before bed, and that late-night TV was more common among short sleepers. Experimental work suggests the arousal TV creates before sleep links it to sleep problems. The AASM suggests turning off electronic devices at least 30 minutes before bedtime. More in screens before bed.

A warm bedroom is better for sleep

Studies have linked a hot, stuffy bedroom with poor sleep, and the study notes that a temperature between 65 and 70 degrees Fahrenheit is often recommended. The AASM also suggests keeping your room at a comfortable, cool temperature. See our guide to the best bedroom temperature for sleep.

Exercising in the evening ruins your sleep

Whether evening exercise ruins your sleep is less clear cut than it sounds. The experts gave it a low falseness rating because the evidence conflicts. Survey data found night-time exercise wasn't linked to sleep problems for most people, and several experiments found no harm to sleep after vigorous evening exercise. The NHS still suggests avoiding exercise in the 4 hours before bed if you have insomnia, so it may be worth testing on yourself.

A myth about what happens while you sleep

Loud snoring is mostly harmless

Loud snoring isn't always harmless, and the experts rated this a myth because snoring is a primary symptom of obstructive sleep apnea, which raises the risk of heart and blood vessel problems when untreated. The AASM says snoring paired with choking, gasping or silent pauses in breathing is a strong sign of sleep apnea, and that daytime sleepiness is another common warning sign. If that sounds familiar, read snoring vs. sleep apnea and see a doctor first.

For ordinary snoring, the NHS suggests nasal strips or dilators when the nose is blocked or narrow, and something to keep the mouth closed when it falls open. In a small randomized trial, nasal strips cut snoring frequency in people with chronic rhinitis, and a small 2022 study of mouth breathers with mild sleep apnea found snoring roughly halved after a week of taping (the research). A 2025 review called these studies small and warned against taping with a blocked nose, so take the nose test first. Neither strips nor tape treat sleep apnea.

Our pick for trying both is the Titan Sleep System, TitanAir nasal strips paired with Titan's bamboo silk mouth tape. Titan says the strips use flexible spring-loaded bands and are designed to pair with the tape, and that every batch is third-party tested and certified PFAS-free.

You'll find more practical guides in our sleep topic hub.

Read next

• Sleep hygiene: the habits with the best evidence
• How to fall asleep faster: what the evidence supports
• 10 snoring myths, and what's actually true

* 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.