Why can't I fall asleep, even when I'm exhausted?

The short answer: being tired and being ready to sleep aren't the same thing. You can be exhausted and still too alert to drop off. Usually that comes down to a busy or anxious mind, a body still in "on" mode, or habits that work against you: going to bed before you're sleepy, napping, late caffeine, or lying there trying hard to sleep. If it happens regularly, it's worth treating as a sleep problem in its own right. At three nights a week for three months or more, it may be chronic insomnia.

You've been yawning since nine. On the sofa your eyes kept closing. Then you brushed your teeth, got into bed, turned off the light, and your brain switched on like someone had flicked a switch.

Now you're going over tomorrow's to-do list, replaying a conversation from lunchtime, and noticing every creak in the house. The more you want to sleep, the further away it gets.

If that's your usual night, this guide is for you. It's specifically about getting to sleep. If your main problem is waking in the night or too early, read our guide to waking at 3am instead. The causes and the first steps are different.

Trouble falling asleep is its own kind of sleep problem

Insomnia isn't one thing. It comes in three broad patterns: trouble getting to sleep, trouble staying asleep, and waking earlier than you want to. Finding it hard to go to sleep is the first sign of insomnia on the standard list, and clinicians sometimes call it sleep-onset insomnia.

Knowing which pattern you have matters, because the triggers differ. Waking at 3am tends to be about alcohol, a full bladder, night sweats or the lighter sleep of the early hours. Lying awake at 11pm is more often about what's happening in your head, your body and your evening.

Why you can be exhausted and still not sleep

It feels like a contradiction. It isn't.

Sleep needs two things at once: enough sleepiness, and a mind and body calm enough to let go. You can have plenty of the first and almost none of the second. Sleep researchers call that second problem hyperarousal, a state of heightened alertness that is one of the main things keeping chronic insomnia going. Most people know it as "tired but wired".

Stress and anxiety are the usual drivers. When you're anxious, your body feels more alert and your mind fills with worrying thoughts; you may notice racing thoughts, tense muscles and a faster heartbeat. None of that is compatible with drifting off, however empty the tank.

Common reasons you can't get to sleep

A mind that won't switch off

For a lot of people, bedtime is the first quiet moment of the day. No messages, no tasks, no noise, so everything you haven't had time to think about arrives at once. Worries you'd handle without blinking at 2pm feel heavier at 11pm, and there's nothing to pull your attention away from them.

Worrying about sleep itself

After a few bad nights, bedtime starts to feel like a test you're about to fail. You calculate how many hours you'll get. You picture tomorrow. That worry alone is enough to keep you up, and it has a habit of getting worse the more nights it happens. We've written about it separately in our guide to sleep anxiety.

Trying too hard

Sleep is an involuntary process. You can't make it happen by effort, but people with insomnia tend to try to control their sleep anyway, and the effort itself is alerting. The harder you try, the more awake you are.

Going to bed before you're sleepy

After a bad night, an early bedtime feels like the sensible way to catch up. In practice it just gives you more time to lie awake. Only go to bed when you feel sleepy; it's better to stay up until you're ready to sleep than to go early and worry about not sleeping.

A bed that's become a place for being awake

If you often lie awake in bed, or use it for scrolling, working or television, your brain learns that bed is somewhere you're alert. Undoing that association, so that bed and bedroom are paired with sleep again, is a core part of insomnia treatment.

Naps

A nap takes the edge off tiredness, which is exactly the problem: it spends the sleepiness you need at bedtime. If you have insomnia, skip daytime naps, even when you're shattered.

Caffeine, nicotine and alcohol

Caffeine and nicotine are stimulants, and both hang around longer than people expect. Keep tea, coffee, cigarettes and alcohol out of the six hours before bed. Caffeine hides in more than coffee: tea, cola, energy drinks and some chocolate all contain it.

Late exercise and big meals

Exercise helps sleep, but timing matters. Aim to be active in the morning or early afternoon rather than in the four hours before bed, and avoid a large meal late in the evening.

Screens before bed

It isn't only the light. Messages, news and social feeds are designed to keep you engaged, which is the opposite of winding down. Put the phone away before bed, not in bed.

An irregular routine

Going to bed and getting up at wildly different times, especially sleeping in at weekends, leaves your body clock unsure when night is. Getting up at the same time every day is one of the most effective habits there is. Shift work and jet lag cause trouble for the same reason.

Your bedroom

Noise, light, a room that's too hot or cold, or an uncomfortable bed all make it harder to drop off. Dark and quiet is the goal.

Restless legs

An uncomfortable urge to move your legs at bedtime, sometimes with tingling, throbbing or itching, may be restless legs syndrome. It's usually worse at night when resting, and it's worth raising with your GP.

What to do when you can't fall asleep

Get up after about 15 minutes

This is the most useful and least intuitive step. If you've been in bed for around 15 minutes and you're not asleep, get up and do something relaxing until you feel sleepy. Go to another room if you can. Keep the lights low and pick something calm and slightly boring: an undemanding book, something gentle to listen to. Go back to bed when you feel sleepy, and repeat as often as you need to.

You don't need to time it. If you've been lying there long enough to feel frustrated, that's the cue.

It works because it stops bed being the place where you lie awake. In CBT for insomnia this is called stimulus control, and it's one of the core techniques.

Don't watch the clock

Every glance turns the night into a countdown, and anxiety about the time only makes insomnia worse. Turn the clock around and put the phone out of reach.

Stop trying

Instead of willing yourself to sleep, let yourself rest without a goal. One CBT-I technique, paradoxical intention, asks people to give up the effort to fall asleep and let go of any concern about being awake. It sounds odd. It works because the effort was the problem.

An evening routine that works with your body

Wind down for an hour

Give yourself at least an hour to relax before bed: a buffer between the day and the night. Dim the lights, put screens away, do something calm. A bath, a book, gentle stretching or a relaxation audio all count.

Give your worries somewhere to go

If your mind races at bedtime, deal with it before you're in bed. Set aside "worry time", 10 or 15 minutes earlier in the evening, to write down what's on your mind and look for next steps. When a worry surfaces later, remind yourself it's already on the list. Even jotting worries down before bed helps: on paper they stop circling.

What helps during the day

Getting to sleep at night starts in the morning.

Get up at the same time every day, including after a bad night and at weekends. This does more for your body clock than almost anything else.

Get outside early. Daylight tells your brain the day has started, which sets your rhythm for the night to come.

Move, ideally earlier rather than later.

Skip the nap.

Watch the caffeine cut-off: nothing with caffeine in the six hours before bed.

When it's more than a few bad nights

Most people struggle to get to sleep during stressful spells, and most of those spells pass. If it's been months, though, you may be dealing with chronic insomnia: trouble sleeping on at least three nights a week for three months or more, with an effect on your days. It's a recognised medical condition, and it's treatable.

UK guidance recommends CBT for insomnia (CBT-I) as the first-line treatment. It's a structured programme that works on exactly the habits and thoughts described above. Our chronic insomnia guide explains how to get it in the UK.

When to see your GP

See your GP if changing your sleep habits hasn't helped, you've had trouble sleeping for months, or it's affecting your daily life. Go sooner if restless legs are keeping you awake, or if difficulty sleeping comes with low mood or anxiety that's getting worse.

Before the appointment, keep a sleep diary for two weeks: what time you went to bed, roughly how long it took to fall asleep, when you got up, and what your day was like.

If it's been months

If getting to sleep has been a nightly battle for a long time, you don't have to keep fighting it alone.

Seona is a regulated UK online clinical service for chronic insomnia. We start by looking at what's really driving your sleep problems. Every case is reviewed by a UK-registered prescriber, and treatment is only prescribed where clinically appropriate. You can read how we assess chronic insomnia first.

Start your consultation

Can't sleep? You're not alone, and it's not your fault.

Frequently asked questions

Why can't I fall asleep even though I'm tired? Being tired isn't the same as being ready to sleep. Stress, anxiety or a busy mind can keep your body and brain alert even when you're exhausted. Naps, late caffeine and going to bed before you're sleepy make it harder still.

What should I do if I can't fall asleep? If you're not asleep after about 15 minutes, get up, go to another room and do something relaxing until you feel sleepy, then go back to bed. Don't watch the clock.

Is it bad to lie in bed awake? Regularly lying awake in bed for long stretches teaches your brain to link the bed with being awake. That's why getting up when you can't sleep is part of CBT for insomnia.

Is trouble falling asleep a sign of insomnia? It can be. Finding it hard to go to sleep is one of the main signs of insomnia. If it happens regularly and affects your days, it's worth getting advice.

Can anxiety stop you falling asleep? Yes. Anxiety brings racing thoughts, tense muscles and a faster heartbeat, all of which make it harder to sleep. Poor sleep then makes anxiety worse.

Should I go to bed earlier if I can't sleep? No. Go to bed only when you feel sleepy. An early bedtime usually just means more time lying awake.

This article is general information, not medical advice. If you're worried about your sleep or your health, speak to a healthcare professional.

References

1. NHS inform. Sleep problems and insomnia self-help guide
2. NHS. Insomnia
3. McNamara S, Spurling BC, Bollu PC. Chronic Insomnia. StatPearls, 2025
4. NHS Every Mind Matters. Sleep; Tackling your worries
5. The Sleep Charity. Sleep anxiety; Sleep diary
6. Broomfield NM, Espie CA. Towards a valid, reliable measure of sleep effort. J Sleep Res, 2005
7. NHS inform. Insomnia
8. NHS. Restless legs syndrome
9. Walker J et al. CBT-I: a primer. 2022
10. Espie CA. Paradoxical intention therapy. 2011