Get morning sunlight
View bright, natural light outside within 30 minutes of waking. This suppresses residual melatonin and anchors your circadian clock to the local day. Even on overcast UK mornings, outdoor light is roughly 10 times brighter than typical indoor lighting. NICE Clinical Knowledge Summaries on insomnia emphasise daylight exposure as a first-line behavioural intervention.
Set a caffeine cutoff
Caffeine has a half-life of around 5 to 7 hours. A 3pm coffee means roughly half its caffeine is still circulating at 9pm. Even if you fall asleep, residual caffeine reduces deep-sleep duration. One controlled study found that 400mg of caffeine 6 hours before bedtime reduced total sleep time by more than an hour [Drake et al., JCSM, 2013].
Keep the bedroom cool and dark
Sleep onset depends on a small drop in core body temperature. Keep your bedroom around 16 to 18°C and ensure total darkness with blackout blinds or an eye mask. Even small amounts of light through closed eyelids suppress melatonin. The NHS recommends a cool, dark, quiet bedroom as the foundation of sleep hygiene.
Digital sunset and worry time
Stop all screen use 60 minutes before bed. Blue light suppresses melatonin and the content keeps the cortex active. If your mind races when you settle, try a "worry time" earlier in the evening: spend 10 minutes writing down what is on your mind, so the brain does not process it at 2am.
The 20-minute rule
If you have been in bed for around 20 minutes and are not asleep, get up. Go to another room and do something quiet in dim light, then return when you feel sleepy. Lying awake trains the brain to associate the bedroom with frustration. Sleep medicine calls this stimulus control therapy, one of the most effective behavioural interventions for chronic insomnia [Bootzin and Epstein, 2011].
Consistent wake time, every day
The single most important sleep habit. Your circadian rhythm is anchored by your wake time, not your sleep time. Keeping it fixed (within about 30 minutes), even after a poor night, stabilises the whole system. Sleeping in on Sunday after a late Saturday is one of the most common reasons Monday-morning fatigue is so brutal: you have effectively given yourself jet lag from your own weekend.
When to see your GP
If sleep problems persist for more than four weeks despite consistent application of these habits, or if you suspect sleep apnoea (loud snoring, witnessed pauses in breathing, daytime sleepiness, morning headaches), see your GP. Untreated sleep apnoea is associated with cardiovascular risk and is highly treatable once identified.
If chronic fatigue is part of the picture and you are not sure whether it is a sleep issue or something else, a structured assessment is worthwhile. Our GP-led fatigue assessment reviews blood-test causes alongside sleep, mood, lifestyle and medication factors in a single consultation.
References
NICE Clinical Knowledge Summaries. Insomnia. NICE CKS
NHS. How to get to sleep. NHS Live Well
Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine. 2013;9(11):1195-1200
Bootzin RR, Epstein DR. Understanding and treating insomnia. Annual Review of Clinical Psychology. 2011;7:435-458
Written by Dr James Coleman, GP and founder of Brooksby Medical. Dr Coleman is a practising General Practitioner who founded Brooksby Medical to give patients direct access to the blood tests and clinical interpretation they need, without waiting lists.
Medically reviewed: May 2026 | Next review due: May 2027
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. If sleep issues are significantly affecting your daily life, or you have concerns about your health, please consult your GP.
Medical disclaimer. This article is for informational purposes and does not constitute medical advice. Blood test results should always be interpreted by a qualified healthcare professional in the context of your individual symptoms, history, and clinical picture. If you have concerns about your health, please consult your GP.