Why Can’t I Sleep? A GP’s Guide to Common Insomnia Causes and Symptoms

When somebody tells me they can’t sleep, the first thing I try to work out is what they actually mean, because it can mean very different things for different people. Are they struggling to get off to sleep? Struggling to stay asleep? Waking multiple times in the night? The strategy from there varies accordingly.

It’s worth knowing how common this is. In the Dreams 2026 Sleep Survey of 2,000 UK adults, people reported an average of 3.4 disturbed nights a week, and around an hour and a half awake on each of those nights. That’s a lot of time lying awake in the dark.

There are three different problems hiding in that one sentence, and they need different answers. Trouble getting off to sleep. Trouble staying asleep. Waking several times a night.

That last one is the pattern people worry about most, and it’s often the least concerning of the three. A lot of the time, people just need reassurance about it.

What we should pay more attention to is waking at random intervals and being awake for long stretches. That’s a different thing.

What disrupts your sleep changes as your life does. What affects a 20-year-old woman is likely to be very different from what affects a 50-year-old woman, which is different again at 75. It really does alter across the life course, which is part of why generic advice so often misses.

This is the one that feeds on itself, and it’s where people get really stuck. Anyone who has experienced insomnia will recognise the feeling… “Now I can’t sleep because I’m worrying that I can’t sleep.”

The Dreams survey bears that out. Racing thoughts or a busy mind was the single most common reason people gave for a broken night, named by 37%, only ahead of stress at 28%. More than 1 in 4 said they worry about not getting a good night’s sleep either most nights or every night.

In younger people especially, anxiety is a real issue now, alongside screens, less time outdoors and less physical activity than previous generations had. If anxiety is the thing keeping you awake, that’s worth treating in its own right rather than only working on the sleep.

Some people are naturally morning larks, while others are night owls. Our chronotype is partly influenced by genetics, and it isn’t simply a matter of discipline.

We live in a world where you’re expected to get up early and function well, and the morning is often the busiest part of the day. If you’re wired the other way, the world isn’t really designed for you, and that can look and feel exactly like insomnia. Teenagers have it hardest because adolescence shifts the body clock later anyway.

Sleep can change throughout the menstrual cycle, with some women noticing poorer sleep in the days leading up to their period. Hormonal fluctuations can also affect sleep during perimenopause, while symptoms such as night sweats and hot flushes can make matters worse.

Hormones can also interact with neurodiversity. For someone with ADHD, that hormonal dip before a period can be particularly disruptive for sleep, and it can create a bit of a perfect storm.

Pregnancy affects sleep significantly, and then there’s the period after the baby arrives, which is its own thing entirely. Dreams cover both in its guides to pregnancy insomnia and menopause and sleep.

In later life, pain and pain medication are far more often the reason behind broken nights. The NHS notes that many medicines can cause insomnia, so if your sleep changed around the time your prescription did, that’s worth raising.

Daytime napping matters more as you get older, too. A long afternoon sleep takes the edge off the sleep pressure you need for that night, so it can quietly make the problem worse.

Alcohol is the one people most often get wrong, because it does help a lot of people drop off, which is exactly why it feels like it works.

Caffeine is worth looking at as well, particularly how late in the day you’re drinking it. A lot of people are surprised by how late in the day it still affects them. The NHS recommends that you stop drinking tea and coffee at least 6 hours before going to bed. It’s also worth thinking about screen use before bed. The light from screens can interfere with your body clock, while stimulating content, scrolling and notifications can make it harder to wind down.

Sometimes, disrupted sleep is caused by an underlying sleep disorder, such as obstructive sleep apnoea. If you’re snoring loudly, waking up gasping or feeling excessively sleepy during the day despite spending enough time in bed, it’s worth speaking to your GP.

Waking in the early hours is something I hear about frequently. One reason it can happen is that our sleep pressure, which builds throughout the day, gradually reduces as we sleep. We also spend less time in deep sleep during the second half of the night, making us more easily disturbed.

Towards morning, cortisol levels naturally begin to rise as our bodies prepare for waking. Together, these changes can make us more vulnerable to waking because of things like pain, a full bladder or a busy mind.

We call this sleep maintenance insomnia. It’s common, it’s well recognised, and it isn’t a sign that something is wrong with you.

Before the list, one thing is worth saying. I went through a period of insomnia in my first year at university, where I just couldn’t get to sleep. I was in university accommodation, so we didn’t have a sofa, but we had chairs. I would put two chairs together, get my duvet and watch a movie, and I could fall asleep in front of the television. As soon as I got into my bedroom, I couldn’t sleep.

What resolved it in the end was somebody recommending a sort of Feng Shui approach. Try sleeping upside down in bed, with the pillow at the bottom and the duvet switched round. Looking back, I suspect I’d developed a negative association between my bed and being unable to sleep. Simply changing my sleeping position may have helped break that association. It’s a good example of how our thoughts and learned behaviours can influence sleep.

So, pick one or two of these rather than attempting all of them. Give whatever you choose a fair run before you judge it. These strategies can be helpful, particularly for occasional sleep difficulties, but if insomnia has become persistent, cognitive behavioural therapy for insomnia (CBT-I) is the treatment with the strongest evidence behind it.

• Get outside early, even on a grey day: Daylight in the first hour of the day helps reset your body clock, and it pays off that evening. Even standing outside looking up at the sky on a dull morning gives you far more light than indoor lighting does.
• Keep your wake-up time steady, weekends included: Getting up at the same time helps anchor your body clock, and it pairs with getting outside early. Even at the weekend.
• Get out of the bedroom if you have been awake 20 minutes: If you’ve been lying awake for a while and are becoming frustrated, get out of bed and do something quiet and relaxing in another room. Return to bed when you feel sleepy again. The aim is to stop your brain from associating your bedroom with the stress of being unable to sleep.

• Leave the clock and your phone alone: Ideally, you’re not looking at clocks at all. Checking the time turns a bad night into arithmetic about how little sleep you’re going to get.
• Make the bedroom dark, quiet and cool: The NHS suggests curtains, blinds, an eye mask or earplugs if you need them. Try to keep activities other than sleep and sex out of the bedroom.
• Move more during the day: It seems counterintuitive when you’re exhausted, and exercising is one of the more reliable ways to improve sleep.
• Look at what you’re drinking and when: Alcohol in the evening and caffeine late in the day both cost you more than they give.
• Keep a sleep diary: What time you go to bed, what time you wake, and the pattern. Plenty of people work out the answer themselves while filling one in.

The NHS says your GP will try to find what’s causing your insomnia, so you get the right treatment. You may be offered cognitive behavioural therapy for insomnia, either face-to-face or as an online programme. It works on the thoughts and behaviours that keep you from sleeping, and it’s the first-line treatment.

Sleeping tablets can help in the short term, but they’re generally not recommended as a long-term solution because of the risks of side effects, tolerance and dependence. Some can also affect the normal structure of sleep. That’s why we usually focus on identifying and treating the underlying cause, with cognitive behavioural therapy for insomnia (CBT-I) being the recommended first-line treatment for persistent insomnia.

When sleep has been bad for a while, the instinct is to go to bed earlier and try to catch up. It often backfires. The sleepiness you need builds up across the day, so turning in early can mean getting into bed before you are tired enough to drop off, and then lying there awake, which is the one thing that makes insomnia worse.