Dr Rebecca Lawson
Why shift work makes sleep so difficult
Your body runs on an internal clock — the circadian rhythm — which uses light, meals and activity to decide when you should feel alert and when you should feel sleepy. Left to its own devices, that clock runs a little longer than 24 hours and is nudged back into line each morning by daylight. Shift work pulls directly against it. A night shift asks you to be capable and clear-headed when your core temperature and alertness are at their lowest, then asks you to sleep when your brain has been given every signal that the day has begun.
This is not a matter of willpower or discipline. Rotating patterns, early starts, long shifts and a bright summer morning on the drive home all work against rest. Nor is it something you simply get used to over the years — most shift workers adapt partially at best. The encouraging part is that sleep can be made far more achievable with small, practical changes to your bedroom, your naps and your caffeine.
Make your bedroom a daytime cave
Sleeping through daylight is a skill, and your environment does most of the work. Aim to make the room dark, cool, quiet and boring — the four things your brain needs to accept that it is night-time.
- Block the light. Blackout curtains or a lined blackout blind are worth the investment. If money is tight, a blackout blind plus a well-fitting eye mask makes a real difference. Even a sliver of light across the pillow can hold back melatonin.
- Cool the room. Around 16–18°C suits most people. Your core temperature has to drop before you can fall asleep, and a warm bedroom makes that harder.
- Deal with noise. Earplugs, a fan or a white-noise app can mask traffic, bin collections and neighbours. Tell your household what your quiet hours are, and put a note on the door if it helps.
- Protect the last hour. Keep the same short wind-down each time: dim lights, a shower, no scrolling. A phone left in another room means one less reason to stay awake.
- Keep some anchor. On days off, try to sleep at roughly the same point in the cycle as your body expects — a lie-in is fine, but flipping entirely to night-time living makes the next rota harder.
Naps: short, planned and strategic
Naps are one of the most effective tools available to shift workers, but length and timing matter. A nap that is too long or too late can leave you groggy and push your main sleep further away.
- Before a night shift, aim for a nap in the late afternoon — either a quick 20–30 minutes, or a full 90-minute cycle if you have the time. Waking mid-cycle tends to bring on sleep inertia, that heavy, disoriented feeling.
- Allow 15 minutes to come round. End the nap at least half an hour before you need to drive or start work.
- On a break, a 20-minute nap in a quiet, dimly lit room — if your workplace allows it — can take the edge off the early hours. Set an alarm.
- Try a caffeine nap. Have a coffee, then sleep for 20 minutes. You wake as the caffeine begins to take effect.
Caffeine timing matters more than caffeine amount
Caffeine has a half-life of roughly five to six hours, and often longer in people who take it regularly. That means a coffee at 2am is still partly in your system at 8am, exactly when you are trying to sleep.
- Front-load it. Have your caffeine at the start of a shift rather than at 4am to push through the slump.
- Set a cut-off. Stop caffeine at least six hours before your planned sleep, and longer if you are sensitive.
- Count the hidden sources. Tea, cola, energy drinks, some painkillers and pre-workout powders all add up.
- Do not lean on it long term. Caffeine masks tiredness rather than replacing sleep, and too much can leave you jittery and worsen the sleep you do get.
Light, food and the journey home
Light is the strongest signal you can send your brain, and you can use it deliberately. Bright light at the start of a shift helps you feel alert. On the way home, do the opposite: wear sunglasses, keep the car cool, and avoid stopping for a chat in bright sunshine. Daylight on the drive back tells your body the day is starting just as you are trying to end it.
Eating patterns matter too. Heavy, rich meals close to bedtime can cause reflux and discomfort, so keep the meal before sleep lighter than you might expect. Avoid alcohol as a sleep aid — it may knock you out faster but fragments sleep and leaves you unrested. Cut back on fluids in the hour before bed so you are not woken by a full bladder. If you arrive home wired and restless, give yourself a 20–30 minute decompression routine in low light before getting into bed, rather than expecting to switch off instantly.
When to get extra support
An occasional rough sleep after a shift is normal and nothing to worry about. It is worth speaking to your GP if you are falling asleep while driving, snoring heavily with pauses or gasping, struggling with insomnia for weeks on end, or feeling persistently low or exhausted even after days off. Mention that you work shifts — it changes the picture considerably.
Occupational health can also advise on rota design. Many people find forward-rotating patterns, where shifts move from days to evenings to nights, easier to cope with than backwards rotation, and some workplaces offer quiet rest spaces for breaks. With a little planning, better rest between rotas is a realistic goal rather than a lucky accident.
