Sleep and Insomnia: The Complete Guide to Better Sleep

Around one in three adults has trouble sleeping at some point, and roughly one in ten has chronic insomnia. Poor sleep affects mood, memory, concentration, weight, blood pressure, immunity and safety on the road and at work. Yet the most effective treatment for insomnia is not a pill. It is a short, structured programme that retrains your brain and body to sleep, and it works for most people.

This guide explains how sleep works, how much you need, why insomnia develops and persists, the evidence-based treatments, what to know about sleeping tablets, and other sleep disorders that need different care.

Why sleep matters

Sleep is not passive downtime. During sleep, the brain consolidates memories, clears waste products, regulates emotions and hormones, and the body repairs tissues and strengthens immunity. Short or poor sleep is linked to higher risks of high blood pressure, heart disease, type 2 diabetes, obesity, depression, anxiety, accidents and reduced immunity. Drowsy driving causes a significant share of road deaths.

How sleep works

Two systems control sleep:

• Sleep pressure (sleep drive): the longer you are awake, the more a chemical called adenosine builds up in the brain, making you sleepy. Sleep clears it. Caffeine works by blocking adenosine.
• The body clock (circadian rhythm): an internal 24-hour clock, set mainly by light, that controls when you feel alert or sleepy, along with hormone release, body temperature and digestion. Melatonin, released in darkness, signals night-time to the body.

Good sleep happens when high sleep pressure lines up with the body clock’s night-time signal. Insomnia often involves disruption to one or both, plus a third factor: a brain that is too alert (hyperarousal).

Sleep stages

Each night you cycle through light sleep, deep sleep and REM (rapid eye movement) sleep, in cycles of about 90 minutes. Deep sleep is concentrated in the first half of the night and REM, when most vivid dreaming happens, in the second half. Brief awakenings between cycles are normal; most are not remembered.

How much sleep do you need?

• Newborns: 14 to 17 hours
• Infants (4 to 11 months): 12 to 15 hours
• Toddlers: 11 to 14 hours
• School-age children: 9 to 11 hours
• Teenagers: 8 to 10 hours
• Adults: 7 to 9 hours
• Older adults (65+): 7 to 8 hours

Needs vary between individuals. A useful test is whether you feel reasonably alert during the day without relying on caffeine. Sleep tends to become lighter and more broken with age, which is normal.

What is insomnia?

Insomnia means difficulty falling asleep, staying asleep, or waking too early, despite having the opportunity to sleep, along with daytime effects such as tiredness, poor concentration, irritability or low mood.

• Short-term insomnia lasts less than three months and is often triggered by stress, illness, pain, bereavement, travel or a new baby.
• Chronic insomnia occurs at least three nights a week for three months or more.

Why insomnia becomes a long-term problem

Insomnia often starts with a trigger, but persists because of the ways we naturally try to cope:

• Going to bed earlier or staying in bed longer to “catch up”, which reduces sleep pressure and leads to more time lying awake
• Napping during the day
• Lying in bed awake, worrying, scrolling or watching TV, which teaches the brain that bed is a place for wakefulness
• Clock-watching and calculating hours left
• Using alcohol to fall asleep, which fragments sleep later in the night
• Relying on caffeine during the day
• Growing anxiety about sleep itself

Over time, the bed becomes associated with frustration and alertness, and the fear of not sleeping keeps the brain on high alert.

Other causes and contributors

• Depression, anxiety, PTSD and bipolar disorder
• Chronic pain, arthritis, reflux, asthma, heart failure and frequent night-time urination
• Menopause (hot flushes and night sweats)
• Pregnancy
• Overactive thyroid
• Medicines such as some antidepressants, steroids, beta blockers, decongestants and stimulants
• Caffeine, nicotine, alcohol and recreational drugs
• Shift work and jet lag
• Noise, light, heat, an uncomfortable bed or a partner who snores

The first-line treatment: CBT for insomnia (CBT-I)

Cognitive behavioural therapy for insomnia (CBT-I) is recommended as the first treatment for chronic insomnia by the American College of Physicians, the European Sleep Research Society, NICE and others. It usually involves four to eight sessions, in person, in groups, or through digital programmes and apps. Around 70 to 80 percent of people improve, and benefits last long after treatment ends, unlike sleeping tablets.

CBT-I has several components:

1. Sleep restriction (sleep window)

This is the most powerful part. Keep a sleep diary for one to two weeks to work out how many hours you actually sleep on average. Then limit your time in bed to that amount (but usually not less than five and a half to six hours). Choose a fixed wake-up time and count back to set your bedtime. For example, if you sleep about six hours and need to get up at 6.30am, your bedtime becomes 12.30am.

At first, you will feel more tired. That is the point: it builds sleep pressure so that sleep becomes deeper and more consolidated. When you are sleeping for at least 85 to 90 percent of the time in bed, extend your window by 15 to 20 minutes a week until you reach the amount that leaves you feeling refreshed. Do not drive or operate machinery if you feel very sleepy, and people with epilepsy, bipolar disorder or certain other conditions should only use sleep restriction under professional guidance.

2. Stimulus control

• Go to bed only when you feel sleepy, not just tired
• Use the bed only for sleep and sex
• If you cannot sleep within about 15 to 20 minutes (estimate, do not clock-watch), get up and go to another room. Do something calm in dim light until you feel sleepy, then return to bed. Repeat as needed
• Get up at the same time every day, including weekends
• Avoid daytime naps, or limit them to 20 minutes before 3pm

3. Cognitive techniques

These address unhelpful thoughts about sleep, such as “If I do not get eight hours, tomorrow will be a disaster” or “I will never sleep normally again”. Learning that the body copes surprisingly well with short sleep, and that one bad night does not ruin the next day, reduces anxiety. Scheduling “worry time” earlier in the evening, writing down worries and a plan, can stop them flooding in at bedtime.

4. Relaxation

Progressive muscle relaxation, slow breathing, body scans and mindfulness can calm the nervous system before bed.

5. Sleep hygiene

Good habits support sleep but rarely fix chronic insomnia on their own. They include keeping the bedroom dark, quiet and cool, avoiding caffeine after midday, limiting alcohol, avoiding heavy meals late at night, getting daylight in the morning, exercising regularly (but not intensely right before bed), and winding down for an hour before bed.

Sleeping tablets: what you should know

Sleeping tablets can help in the short term, for example during a crisis, but they are not a long-term solution for most people.

• Z-drugs (zopiclone, zolpidem) and benzodiazepines (temazepam, diazepam): recommended only for short periods, usually no more than two to four weeks. They can cause next-day drowsiness, falls and fractures in older people, memory problems, complex sleep behaviours such as sleepwalking, and dependence. Stopping after long-term use should be done gradually with support.
• Sedating antihistamines (sold over the counter): can cause next-day grogginess, confusion in older adults and tolerance develops quickly.
• Melatonin: helpful for jet lag, circadian rhythm disorders and some people over 55 with insomnia. Evidence for general insomnia is modest. Product quality varies in countries where it is sold as a supplement.
• Sedating antidepressants such as low-dose doxepin, mirtazapine or trazodone are sometimes used, particularly if depression is present.
• Orexin receptor antagonists (daridorexant, lemborexant, suvorexant): a newer class that blocks wake-promoting signals. Daridorexant is approved in several countries for chronic insomnia when CBT-I is not available or has not worked.

Never combine sleeping tablets with alcohol or opioids, and do not drive if you feel drowsy.

Other sleep disorders

Obstructive sleep apnoea

In sleep apnoea, the airway repeatedly closes during sleep, causing pauses in breathing, loud snoring, gasping and choking, and frequent brief awakenings. People often wake unrefreshed, feel very sleepy during the day, and may have morning headaches. Sleep apnoea raises the risk of high blood pressure, heart disease, stroke and road accidents. It is very common, particularly in people with obesity, a large neck, or a small jaw. Treatment includes weight loss, a CPAP machine that keeps the airway open, mouth devices and, in some cases, surgery. A sleep study confirms the diagnosis.

Restless legs syndrome

An uncomfortable urge to move the legs, worse in the evening and at rest, relieved by movement. It can be linked to low iron, kidney disease, pregnancy and some medicines. Checking ferritin and replacing iron if low often helps.

Circadian rhythm disorders

Some people, especially teenagers and young adults, have a naturally late body clock (delayed sleep phase) and cannot fall asleep until very late. Morning bright light, evening dim light, and carefully timed melatonin can shift the clock earlier.

Narcolepsy

A rare condition causing severe daytime sleepiness, sudden sleep attacks, and sometimes sudden muscle weakness triggered by emotions (cataplexy). It needs specialist assessment.

Parasomnias

Sleepwalking, night terrors, sleep paralysis and acting out dreams. Acting out dreams violently in older adults (REM sleep behaviour disorder) should be assessed by a specialist.

Sleep and shift work

Night shifts force people to sleep against their body clock. Shift workers have higher rates of insomnia, sleepiness, accidents and long-term health problems.

• Protect a main sleep block after night shifts, in a dark, quiet, cool room with blackout blinds, an eye mask and earplugs
• Wear sunglasses on the way home after a night shift to reduce morning light exposure
• A short nap before a night shift and, where allowed, a 20-minute nap during breaks can reduce fatigue
• Use caffeine early in the shift, not in the last few hours
• Avoid driving when very sleepy; consider a nap or alternative transport
• Rotate shifts forwards (days, then evenings, then nights) when possible

Sleep across life

Children and teenagers

Consistent bedtimes, a calm routine, limiting screens before bed and keeping devices out of bedrooms help children sleep. Teenagers’ body clocks shift later, so early school start times can cause chronic sleep deprivation.

Pregnancy and new parents

Sleep is often disrupted by discomfort, needing to urinate and later by night feeds. Sleep when the baby sleeps when possible, share night duties, and ask for help.

Menopause

Hot flushes, night sweats and mood changes affect sleep. Treating symptoms, including with HRT where suitable, and CBT-I can help.

Older adults

Sleep becomes lighter, with more awakenings and earlier waking. Daytime activity, outdoor light, limiting naps and reviewing medicines help. Sleeping tablets carry particular risks of falls and confusion in older people.

A four-week plan for better sleep

• Week 1: keep a sleep diary. Fix a wake-up time, seven days a week. Get outside in daylight within an hour of waking.
• Week 2: set a sleep window based on your diary. Get up if you cannot sleep. Stop naps. Move caffeine before midday.
• Week 3: keep the window; add a wind-down routine and scheduled worry time in the early evening.
• Week 4: if you are sleeping most of the time in bed, extend the window by 15 minutes. Keep going until you feel refreshed.

When to see a healthcare provider

• Insomnia lasting more than a few weeks and affecting your daily life
• Loud snoring with pauses in breathing or gasping, or severe daytime sleepiness
• Falling asleep while driving or at unsafe moments
• Low mood, anxiety or thoughts of self-harm
• Unusual behaviours during sleep
• Restless legs that disturb your sleep

Your bedroom and wind-down routine

Your environment and the hour before bed send powerful signals to your brain about whether it is time to sleep.

• Darkness: use blackout curtains or an eye mask. Light, including from streetlamps and standby lights, can suppress melatonin.
• Temperature: a slightly cool room, around 16 to 19°C for many people, supports the natural drop in body temperature that comes with sleep.
• Noise: earplugs, a fan or white noise can mask disruptive sounds.
• Comfort: a supportive mattress and pillows that suit how you sleep.
• Clock: turn the clock to face away from you so you cannot check the time during the night.
• Wind-down: spend the last 30 to 60 minutes before bed doing something calm in dim light, such as reading a paper book, listening to music or a podcast, gentle stretching or a warm shower.
• Worry pad: keep a notebook by the bed to jot down thoughts or tasks so you do not have to hold them in your head.

Food, drink and sleep

• Caffeine: stays in the body for many hours; half of the caffeine from a mid-afternoon coffee may still be circulating at bedtime. Remember that tea, cola, energy drinks and chocolate also contain caffeine.
• Alcohol: may make you drowsy but leads to lighter, more broken sleep and early waking.
• Heavy or spicy meals: eating a large meal within two to three hours of bed can cause reflux and discomfort.
• Going to bed hungry: can also wake you; a small snack such as a banana, yoghurt or a slice of toast is fine.
• Fluids: reduce drinks in the last hour or two before bed if you wake to pass urine.
• Nicotine: is a stimulant, and withdrawal during the night can disturb sleep.

Exercise and daylight

Regular physical activity is one of the most reliable ways to improve sleep quality. Exercise increases sleep pressure, reduces anxiety and helps regulate the body clock. Morning or afternoon exercise outdoors gives a double benefit, because daylight is the strongest signal to set the body clock. Even on cloudy days, outdoor light is far brighter than indoor lighting. Try to get at least 20 to 30 minutes of daylight early in the day, particularly in winter. Vigorous exercise right before bed may make it harder for some people to fall asleep, but gentle activity such as stretching or yoga is fine.

Sleep and mental health

Insomnia and mental health problems are closely linked in both directions. Insomnia is a risk factor for developing depression and anxiety, and it is also one of their most common symptoms. Treating insomnia with CBT-I can improve depression and anxiety symptoms, and in some studies has reduced the risk of future depression. If you are struggling with persistent low mood, hopelessness or anxiety along with poor sleep, seek help for both. If you have thoughts of harming yourself, contact emergency services or a crisis line immediately.

Napping: friend or foe?

For people without insomnia, a short nap of 10 to 20 minutes in the early afternoon can boost alertness without affecting night-time sleep. Longer naps, or naps later in the day, reduce sleep pressure and make it harder to fall asleep at night. If you have insomnia, avoid naps while you work on your sleep, unless you are at risk of falling asleep while driving or working, in which case a brief safety nap is the better choice. Shift workers are the exception; planned naps before and during night shifts can improve safety.

Supplements and herbal remedies

Many products are marketed for sleep, including valerian, chamomile, lavender, magnesium and CBD. Evidence for most is limited or inconsistent, and product quality varies widely. Some interact with other medicines. They are unlikely to fix chronic insomnia, but some people find calming routines such as a warm, caffeine-free herbal drink helpful as part of winding down. Check with a pharmacist before taking supplements, particularly if you are pregnant, breastfeeding or take other medicines.

Remember that sleep improves gradually. Most people notice the biggest changes after three to four weeks of consistent effort, so keep going even if the first week feels hard.

Frequently asked questions

Is it bad to look at my phone in bed?

The light from screens has a smaller effect than once thought, but scrolling keeps the brain engaged and delays sleep. Keep phones out of reach and use bed for sleep.

Can I catch up on sleep at weekends?

A little extra sleep can help, but big lie-ins shift your body clock and make Sunday nights harder.

Does alcohol help sleep?

It may help you fall asleep but fragments sleep later in the night and worsens snoring and sleep apnoea.

Is waking at night normal?

Yes. Brief awakenings are normal. Problems arise when you cannot get back to sleep or worry about waking.

Do sleep trackers help?

They can show patterns but are not very accurate at measuring sleep stages, and some people become more anxious using them.

But I have had insomnia for years. Can it really be fixed?

Yes. CBT-I works even for people who have had insomnia for decades, including those using sleeping tablets and those with depression, anxiety or chronic pain. The early weeks can be tough, because sleep restriction makes you tired, but that tiredness is what rebuilds your natural sleep drive. Many people say it changed their lives.

Related: Insomnia and sleep hygiene tips · Sleep apnoea · Sleeping pills: risks and better options

Sources: American Academy of Sleep Medicine, European Sleep Research Society insomnia guideline (2023), American College of Physicians guideline on chronic insomnia, National Institute for Health and Care Excellence, World Health Organization, National Sleep Foundation.