Insomnia: Causes, Symptoms and Treatment

What is insomnia?

Insomnia is difficulty getting to sleep, staying asleep, or waking too early and not getting back to sleep, despite having the chance to sleep. Crucially, it affects how you feel and function during the day.

Short-term insomnia, lasting days to weeks, is very common and often linked to stress. Chronic insomnia is when sleep problems happen at least three nights a week for at least three months. It affects around one in ten adults.

Symptoms of insomnia

• Taking a long time to fall asleep
• Waking during the night and struggling to get back to sleep
• Waking too early
• Feeling unrefreshed after sleep
• Daytime tiredness, low energy, irritability, poor concentration or memory
• Worrying about sleep, and dreading bedtime

Causes of insomnia

Sleep researchers often describe insomnia using three groups of factors:

• Predisposing: things that make someone more vulnerable, such as a tendency to worry, being a light sleeper, older age, or family history.
• Precipitating: what starts it, such as stress, illness, pain, a new baby, grief, shift work or travel.
• Perpetuating: what keeps it going after the trigger has passed, such as spending longer in bed to “catch up”, napping, irregular sleep times, clock-watching, and worrying about sleep.

The perpetuating factors are why insomnia can continue long after the original cause has gone, and they’re the main target of treatment.

Other conditions to consider

• Pain, which commonly disrupts sleep. See chronic pain and sleep.
• Anxiety and depression
• Sleep apnoea, restless legs and other sleep disorders
• Hot flushes, reflux, needing to pass urine at night
• Caffeine, alcohol and some medicines

Treatment that works

CBT for insomnia (CBT-I)

European and American guidelines recommend cognitive behavioural therapy for insomnia as the first treatment for chronic insomnia in adults. It combines changes to sleep timing, getting out of bed when you can’t sleep, managing racing thoughts and relaxation. It works for most people, and its benefits last after treatment ends. See CBT for insomnia.

Sleep habits

Good sleep habits support treatment but usually aren’t enough on their own for chronic insomnia. See our sleep hygiene checklist.

Medicines

Sleep medicines can help for short periods in some situations, but they don’t fix the underlying pattern and can cause problems with longer use, including dependence and next-day drowsiness. Guidelines recommend them only short term, if at all. Talk to your GP before starting or stopping any sleep medicine.

When to see a GP

See a GP if poor sleep lasts more than a few weeks or affects your mood, work or safety, if you snore loudly or stop breathing in your sleep, or if you’re falling asleep during the day.

References

1. Morin CM, Drake CL, Harvey AG, et al. Insomnia disorder. Nat Rev Dis Primers. 2015;1:15026.
2. Riemann D, Espie CA, Altena E, et al. The European Insomnia Guideline: An update on the diagnosis and treatment of insomnia 2023. J Sleep Res. 2023;32(6):e14035.
3. Qaseem A, Kansagara D, Forciea MA, et al. Management of Chronic Insomnia Disorder in Adults: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 2016;165(2):125-33.
4. Trauer JM, Qian MY, Doyle JS, et al. Cognitive Behavioral Therapy for Chronic Insomnia: A Systematic Review and Meta-analysis. Ann Intern Med. 2015;163(3):191-204.
5. healthdirect. Insomnia.
6. Sleep Health Foundation. Sleep Health Foundation.