https://sleepfacts.uk/ How sleep works, why it matters for your health, what actually helps you sleep better and which sleep aids work, graded by the quality of the evidence. en-gb https://sleepfacts.uk/sleep-better/alcohol/ https://sleepfacts.uk/sleep-better/alcohol/ Wed, 04 Nov 2026 00:00:00 GMT Alcohol helps you fall asleep faster and deepens sleep in the first half of the night, but as it wears off, sleep becomes broken and shallow in the second half, with less REM sleep. The net effect, especially with more than a drink or two, is worse sleep. The NHS advises no alcohol for at least 6 hours before bed. https://sleepfacts.uk/sleep-better/caffeine/ https://sleepfacts.uk/sleep-better/caffeine/ Wed, 04 Nov 2026 00:00:00 GMT Caffeine blocks adenosine, the chemical that builds sleep pressure, and its effects last for hours: about half is still in your body 5 hours later. In a home trial, a strong dose taken 6 hours before bed still significantly disturbed sleep. The NHS advises no tea or coffee for at least 6 hours before bed, and sensitive people may need to stop earlier. https://sleepfacts.uk/sleep-problems/cbt-for-insomnia/ https://sleepfacts.uk/sleep-problems/cbt-for-insomnia/ Wed, 04 Nov 2026 00:00:00 GMT CBT for insomnia (CBT-I) is a short course of talking therapy, usually 4 to 8 sessions, that changes the habits and thoughts that keep insomnia going. A review of 20 trials found it helped people fall asleep about 19 minutes faster and spend 26 fewer minutes awake at night. NICE recommends it as the first treatment for long-term insomnia, and it works without pills. https://sleepfacts.uk/sleep-aids/chamomile/ https://sleepfacts.uk/sleep-aids/chamomile/ Wed, 04 Nov 2026 00:00:00 GMT Maybe, a little. A review of trials found chamomile improved how well people rated their sleep, but the only trial in people with insomnia found no clear benefit. A cup of chamomile tea is caffeine-free and harmless for most people, so it can be a pleasant part of winding down, as long as you don't expect it to treat insomnia. https://sleepfacts.uk/sleep-better/warm-bath/ https://sleepfacts.uk/sleep-better/warm-bath/ Wed, 04 Nov 2026 00:00:00 GMT Yes, modestly. A review of 17 studies found that a warm bath or shower at about 40 to 42.5°C taken 1 to 2 hours before bed helped people fall asleep faster and rate their sleep better, even when it lasted only 10 minutes. It works by warming the skin so that the body cools down faster afterwards, which is a natural signal for sleep. https://sleepfacts.uk/benefits/weight-and-appetite/ https://sleepfacts.uk/benefits/weight-and-appetite/ Wed, 04 Nov 2026 00:00:00 GMT Probably, a little. In lab trials, people whose sleep was cut ate about 385 more calories a day without burning more, and two nights of short sleep lowered the fullness hormone leptin by 18% and raised the hunger hormone ghrelin by 28%. Long-term studies link short sleep with gradual weight gain, though the effect is modest. https://sleepfacts.uk/benefits/dementia/ https://sleepfacts.uk/benefits/dementia/ Wed, 04 Nov 2026 00:00:00 GMT Possibly. In the Whitehall II study of 7,959 British civil servants followed for 25 years, people who regularly slept 6 hours or less in their 50s and 60s were about 30% more likely to develop dementia. Lab studies suggest deep sleep helps clear a protein linked to Alzheimer's. But early brain changes may disturb sleep years before symptoms, so cause and effect are unclear. https://sleepfacts.uk/sleep-better/exercise/ https://sleepfacts.uk/sleep-better/exercise/ Wed, 04 Nov 2026 00:00:00 GMT Regular exercise improves sleep modestly. A review of 66 studies found small benefits for how long and how deeply people slept and a moderate reduction in waking at night. Evening exercise doesn't harm sleep for most people, except possibly vigorous exercise that ends within about an hour of bed. https://sleepfacts.uk/how-sleep-works/how-much-sleep-do-you-need/ https://sleepfacts.uk/how-sleep-works/how-much-sleep-do-you-need/ Wed, 04 Nov 2026 00:00:00 GMT Most adults need 7 to 9 hours a night, and people over 65 need 7 to 8. Children need more: 9 to 11 hours at primary school age and 8 to 10 for teenagers. Large studies link regularly sleeping under about 6 hours with worse health, and long sleep, often 9 hours or more, is also linked with illness, though partly because illness causes it. https://sleepfacts.uk/how-sleep-works/ https://sleepfacts.uk/how-sleep-works/ Wed, 04 Nov 2026 00:00:00 GMT Sleep comes in cycles of about 90 minutes, each passing through light sleep, deep sleep and dreaming (REM) sleep. When you feel sleepy depends on two things: pressure that builds the longer you are awake, and a body clock that runs on a roughly 24-hour cycle set by daylight. Most adults need 7 to 9 hours a night. https://sleepfacts.uk/sleep-better/ https://sleepfacts.uk/sleep-better/ Wed, 04 Nov 2026 00:00:00 GMT The changes with the best evidence are a fixed wake time, daylight in the morning, no caffeine for at least 6 hours before bed, little or no alcohol in the evening, regular exercise and a cool, dark, quiet bedroom. Each helps a little on its own. For insomnia lasting months, these tips alone rarely work: CBT for insomnia is the treatment to try. https://sleepfacts.uk/sleep-problems/insomnia/ https://sleepfacts.uk/sleep-problems/insomnia/ Wed, 04 Nov 2026 00:00:00 GMT Insomnia means regularly struggling to fall asleep, stay asleep or sleep long enough, and feeling the effects in the day. When it lasts 3 months or more it's called long-term insomnia. It's very common: over a third of UK adults in one study had symptoms. The best treatment is CBT for insomnia, which NICE recommends before sleeping pills. https://sleepfacts.uk/sleep-problems/jet-lag/ https://sleepfacts.uk/sleep-problems/jet-lag/ Wed, 04 Nov 2026 00:00:00 GMT Jet lag happens when your body clock is out of step with the time at your destination after a long flight. It usually improves within a few days. To recover faster, switch to local time quickly, get daylight during the day and avoid napping. Melatonin reduced jet lag in most trials, though the NHS doesn't recommend it because it judges the evidence too limited. https://sleepfacts.uk/how-sleep-works/larks-and-owls/ https://sleepfacts.uk/how-sleep-works/larks-and-owls/ Wed, 04 Nov 2026 00:00:00 GMT Your chronotype is the time of day your body clock prefers you to sleep. It is partly inherited, shifts later in the teenage years and earlier with age. Most people sit in the middle. Evening types aren't lazy, but their natural timing clashes with school and work hours, and in a UK study of 433,000 adults, definite evening types had a 10% higher risk of death over six and a half years. https://sleepfacts.uk/sleep-aids/lavender/ https://sleepfacts.uk/sleep-aids/lavender/ Wed, 04 Nov 2026 00:00:00 GMT There is some evidence that lavender helps, but it's thin. Lavender oil capsules eased anxiety and the restless, broken sleep that goes with it in a 10-week trial. In a small trial of students, a lavender patch at night improved sleep quality more than a blank patch. No good trial shows it treats insomnia. https://sleepfacts.uk/sleep-aids/magnesium/ https://sleepfacts.uk/sleep-aids/magnesium/ Wed, 04 Nov 2026 00:00:00 GMT Possibly a little, mostly in older people. A review of three small trials in 151 older adults found magnesium helped people fall asleep about 17 minutes faster, but the evidence was low quality and total sleep didn't change significantly. The NHS says 400 mg a day or less from supplements is unlikely to cause harm. https://sleepfacts.uk/sleep-aids/melatonin/ https://sleepfacts.uk/sleep-aids/melatonin/ Wed, 04 Nov 2026 00:00:00 GMT Melatonin is the hormone that tells your body it is night. As a tablet, it helps a little: a review of 19 studies found people fell asleep about 7 minutes faster and slept 8 minutes longer. Trials suggest it helps more with jet lag. In the UK it is prescription only, mainly for short-term use in people aged 55 and over. https://sleepfacts.uk/sleep-better/naps/ https://sleepfacts.uk/sleep-better/naps/ Wed, 04 Nov 2026 00:00:00 GMT Short naps of about 10 to 20 minutes improve alertness and performance for an hour or more, with little grogginess afterwards. Longer naps reach deep sleep and can leave you groggy, and naps late in the afternoon can make it harder to sleep at night. If you have insomnia, avoid napping. https://sleepfacts.uk/sleep-aids/antihistamines/ https://sleepfacts.uk/sleep-aids/antihistamines/ Wed, 04 Nov 2026 00:00:00 GMT Sedating antihistamines such as diphenhydramine (Nytol Original, Boots Sleepeaze) and promethazine (Sominex, Phenergan) make you drowsy, but trials show only small effects on sleep, and the body gets used to them quickly. They can leave you groggy the next day. The NHS says to speak to a doctor if you need them for more than 2 weeks. https://sleepfacts.uk/sleep-problems/restless-legs/ https://sleepfacts.uk/sleep-problems/restless-legs/ Wed, 04 Nov 2026 00:00:00 GMT Restless legs syndrome causes an overwhelming urge to move your legs, usually with uncomfortable tingling or crawling feelings, which comes on when resting in the evening or at night and eases with movement. It's linked to iron and dopamine in the brain. Checking for low iron, cutting caffeine and alcohol, and stretching or a warm bath can help. Medicines are available for severe cases. https://sleepfacts.uk/sleep-better/screens-and-blue-light/ https://sleepfacts.uk/sleep-better/screens-and-blue-light/ Wed, 04 Nov 2026 00:00:00 GMT Bright light in the evening, including from screens, holds back melatonin and shifts the body clock later. In a lab study, reading on a bright tablet for four hours a night delayed sleep and the body clock compared with a printed book. In everyday life the light effect of a phone is smaller; what you do on it, and how long it keeps you up, probably matters more. https://sleepfacts.uk/sleep-problems/shift-work/ https://sleepfacts.uk/sleep-problems/shift-work/ Wed, 04 Nov 2026 00:00:00 GMT Night and early shifts force you to sleep when your body clock is set for waking, so sleep after a night shift is often short and light. Shift work is linked to accidents, weight gain, type 2 diabetes and heart disease. Protecting a dark, quiet daytime sleep, a nap before night shifts, and timing light and caffeine carefully all help. https://sleepfacts.uk/sleep-aids/ https://sleepfacts.uk/sleep-aids/ Wed, 04 Nov 2026 00:00:00 GMT Most sleep aids sold in the UK have only weak evidence: magnesium, valerian, chamomile, lavender and sedating antihistamines such as Nytol help little, if at all, in trials. Melatonin shortens the time to fall asleep by about 7 minutes and works better for jet lag. Prescription sleeping pills work in the short term but carry real risks. For long-term insomnia, CBT for insomnia beats all of them. https://sleepfacts.uk/benefits/mood-and-mental-health/ https://sleepfacts.uk/benefits/mood-and-mental-health/ Wed, 04 Nov 2026 00:00:00 GMT Poor sleep and mental health problems feed each other. Insomnia roughly doubles the risk of later depression, and in a UK trial of 3,755 students, treating insomnia with online CBT also reduced paranoia, hallucinatory experiences, depression and anxiety. That suggests better sleep can improve mental health, not just the other way round. https://sleepfacts.uk/benefits/type-2-diabetes/ https://sleepfacts.uk/benefits/type-2-diabetes/ Wed, 04 Nov 2026 00:00:00 GMT In studies of over 100,000 people, short sleep raised the risk of developing type 2 diabetes by about 28%, and trouble staying asleep by 84%. Lab trials show why: a few nights of short or shallow sleep make the body less sensitive to insulin, so blood sugar control worsens even in healthy young people. https://sleepfacts.uk/benefits/heart-and-blood-pressure/ https://sleepfacts.uk/benefits/heart-and-blood-pressure/ Wed, 04 Nov 2026 00:00:00 GMT In studies following nearly half a million people, those who regularly slept less than about 6 hours were 48% more likely to develop or die of coronary heart disease and 15% more likely to have a stroke. Long sleep was linked with higher risk too. Lab trials show sleep loss raises stress hormones and nervous system activity, which helps explain the link. https://sleepfacts.uk/benefits/immune-system/ https://sleepfacts.uk/benefits/immune-system/ Wed, 04 Nov 2026 00:00:00 GMT In a trial where 164 healthy adults were given a cold virus, those who had slept under 6 hours a night the week before were about four times as likely to develop a cold as those who slept over 7 hours. Short sleep has also been linked with weaker responses to flu and hepatitis B vaccines. https://sleepfacts.uk/sleep-problems/sleep-apnoea/ https://sleepfacts.uk/sleep-problems/sleep-apnoea/ Wed, 04 Nov 2026 00:00:00 GMT Obstructive sleep apnoea is when the throat repeatedly closes during sleep, stopping breathing for seconds at a time. Signs are loud snoring, gasping or choking, pauses in breathing and heavy daytime tiredness. It's common and often undiagnosed. A GP can refer you for a home sleep test, and treatment, often a CPAP machine, is free on the NHS and works well. https://sleepfacts.uk/how-sleep-works/sleep-and-ageing/ https://sleepfacts.uk/how-sleep-works/sleep-and-ageing/ Wed, 04 Nov 2026 00:00:00 GMT Healthy adults get steadily less deep sleep and REM sleep with age, take a little longer to fall asleep and wake more often in the night. Most of these changes happen by about 60. Over-65s still need around 7 to 8 hours. Waking tired every day, loud snoring or long-term insomnia aren't a normal part of ageing and are worth raising with a GP. https://sleepfacts.uk/sleep-better/sleep-hygiene/ https://sleepfacts.uk/sleep-better/sleep-hygiene/ Wed, 04 Nov 2026 00:00:00 GMT Sleep hygiene means habits that support sleep, like a regular schedule, avoiding late caffeine and alcohol, and a dark, quiet bedroom. Most individual tips have some evidence behind them. But as a treatment for chronic insomnia, a list of tips on its own does little, and US guidelines advise against relying on it. It works best as part of CBT for insomnia. https://sleepfacts.uk/sleep-problems/ https://sleepfacts.uk/sleep-problems/ Wed, 04 Nov 2026 00:00:00 GMT The commonest sleep problems are insomnia, obstructive sleep apnoea and restless legs, along with the body-clock problems caused by shift work and jet lag. Insomnia is best treated with CBT for insomnia rather than pills. Loud snoring with pauses in breathing, or heavy daytime sleepiness, can mean sleep apnoea, which needs a GP referral and is very treatable. https://sleepfacts.uk/benefits/memory-and-learning/ https://sleepfacts.uk/benefits/memory-and-learning/ Wed, 04 Nov 2026 00:00:00 GMT This is the best-proven benefit of sleep. Dozens of lab trials show that losing sleep impairs attention, reaction time and working memory, and that sleep after learning helps fix new memories. In one trial, people limited to 6 hours a night for two weeks became as impaired as people who had missed a night's sleep, while feeling only slightly sleepy. https://sleepfacts.uk/sleep-aids/sleeping-pills/ https://sleepfacts.uk/sleep-aids/sleeping-pills/ Wed, 04 Nov 2026 00:00:00 GMT Prescription sleeping pills such as zopiclone and zolpidem work in the short term: in older people they added about 25 minutes of sleep a night. But they cause next-day drowsiness, falls and memory problems, and the body gets used to them, so UK doctors prescribe them for no more than about 4 weeks. NICE recommends CBT for insomnia first. https://sleepfacts.uk/sleep-better/bedroom-temperature/ https://sleepfacts.uk/sleep-better/bedroom-temperature/ Wed, 04 Nov 2026 00:00:00 GMT A cool bedroom helps. Lab studies show that heat, especially humid heat, increases waking and reduces deep and REM sleep, because your body needs to shed heat to sleep well. Around 16 to 18°C is a commonly suggested range for a bedroom, but there is no tested single ideal: what matters is that you feel comfortably cool under your bedding. https://sleepfacts.uk/how-sleep-works/stages-of-sleep/ https://sleepfacts.uk/how-sleep-works/stages-of-sleep/ Wed, 04 Nov 2026 00:00:00 GMT Sleep has four stages: two of light sleep (N1 and N2), deep sleep (N3) and REM sleep, when most dreaming happens. You cycle through them about every 90 minutes, four to six times a night. Deep sleep comes mostly in the first half of the night and REM in the second. In adults, light N2 sleep makes up about half the night. https://sleepfacts.uk/sleep-aids/valerian/ https://sleepfacts.uk/sleep-aids/valerian/ Wed, 04 Nov 2026 00:00:00 GMT The evidence is weak and mixed. One review of 16 studies found people were more likely to report better sleep, but the studies were small and biased towards positive results. A later review of 18 trials found no measurable difference in time to fall asleep. Valerian is generally safe short term, but don't mix it with alcohol or other sedatives. https://sleepfacts.uk/sleep-aids/weighted-blankets/ https://sleepfacts.uk/sleep-aids/weighted-blankets/ Wed, 04 Nov 2026 00:00:00 GMT Possibly, but the evidence rests mainly on one trial. In Sweden, 120 people with depression, bipolar disorder, anxiety or ADHD who slept with a heavy chain blanket for 4 weeks had much less insomnia than those with a light one. It hasn't been repeated in people without these conditions. Weighted blankets are safe for most adults but not for babies or young children. https://sleepfacts.uk/sleep-problems/when-to-see-a-gp/ https://sleepfacts.uk/sleep-problems/when-to-see-a-gp/ Wed, 04 Nov 2026 00:00:00 GMT See a GP if you've had trouble sleeping for months, it affects your daily life, or self-help hasn't worked. See one sooner if someone notices you stop breathing or gasp in your sleep, you fall asleep in the day without meaning to, or restless legs keep you awake. Keep a two-week sleep diary to take along. https://sleepfacts.uk/benefits/ https://sleepfacts.uk/benefits/ Wed, 04 Nov 2026 00:00:00 GMT Enough sleep clearly helps attention, learning and memory, and lab trials show that cutting sleep raises appetite, blood pressure and blood sugar and weakens the response to vaccines. Large studies link regular short sleep with heart disease, type 2 diabetes, colds, depression and dementia, though they can't fully prove cause and effect. https://sleepfacts.uk/how-sleep-works/body-clock/ https://sleepfacts.uk/how-sleep-works/body-clock/ Wed, 04 Nov 2026 00:00:00 GMT A master clock in the brain runs on a cycle of just over 24 hours and is reset every day, mainly by light reaching your eyes. It times when you feel sleepy, when melatonin is released and when your body temperature dips. Bright light in the morning helps you sleep at night; bright light late in the evening pushes your clock later.